diff --git a/Admin.php b/Admin.php
index 597c197..1cbfb8e 100644
--- a/Admin.php
+++ b/Admin.php
@@ -28,64 +28,62 @@ if ($_SESSION['user_type'] != "Lecturer" && $_SESSION['user_type'] != "Admin") {
 	<div class="col-md-6">
 
            <!-- Nav tabs -->
-	    <ul class="nav nav-tabs">
+	    <ul class="nav nav-tabs" id="myTab">
+
 		<li class="nav-item">
-		    <a class="nav-link active" id="home" href="#home">Create TA account</a>
+		    <a class="nav-link active" href="#tab-student-accounts" id="batch_tab">Create student accounts</a>
 		</li>
 
 		<li class="nav-item">
-		    <a class="nav-link" href="#menu1" id="batch_tab">Batch create student accounts</a>
+		    <a class="nav-link" href="#tab-ins-accounts">Create instructor account</a>
 		</li>
 
 		<li class="nav-item">
-		    <a class="nav-link" href="#menu2" id="existing_accounts_tab">Existing accounts</a>
+		    <a class="nav-link" href="#tab-existing-accounts" id="existing_accounts_tab">Existing accounts</a>
 		</li>
 	    </ul>
 
             <!-- Tab panes -->
 	    <div class="tab-content">
 
-		<div id="home" class="tab-pane active"><br>
+		<!-- code contributed by Xu Xiaopeng (https://github.com/xxp1999) -->
+		<div id="tab-student-accounts" class="tab-pane active" style="margin-top:5px">
+		    <p class="text-muted">Copy & paste student number to the following box, and separate two student numbers with a space.</p>
+		    <form action="batch_insert.php" method="post" id="batch_form">
+			<textarea cols="60" rows="16" name="users" required=""></textarea>
+			<button type="submit" class="btn btn-primary" id="register_btn">Register students</button>
+		    </form>
+		</div>
+
+		<div id="tab-ins-accounts" class="tab-pane"><br>
 
 		    <?php
 		    if ($_SESSION['user_type'] == "Lecturer") {
-
-			echo "<b>Create TA Accounts </b>";
-
+			echo "<p class=\"text-muted\">Create TA Accounts</p>";
 		    }
 		    else if($_SESSION['user_type'] == "Admin"){
-			echo "<b>Create Lecturer Accounts </b>";
+			echo "<p class=\"text-muted\">Create Lecturer Accounts</p>";
 		    }
 
 		    ?>
 		    <form method="post" action="Script.php" id="create_account_form">
 			<input type="hidden" name="frm_createlecturrer" value="true" required="" />
 			Full name
-			<input type="text" name="fullname" placeholder="Full Name" class="form-control" required="">
+			<input type="text" name="fullname" placeholder="Full Name" class="form-control" required=""> <br>
 			Email
-			<input type="text" name="email" placeholder="Email / Student Number" class="form-control" required="">
-
+			<input type="text" name="email" placeholder="Email / Student Number" class="form-control" required=""> <br>
 			Passport number/ID (used as the initial password)
-			<input type="text" class="form-control" name="passport" placeholder="Passport No./ID" required="">
-			<br> User type:
-
+			<input type="text" class="form-control" name="passport" placeholder="Passport No./ID" required=""> <br>
+			User type:
 			<?php
-
 			if ($_SESSION['user_type'] == "Lecturer") {
-
 			    echo ' <input type="radio" name="type" value="TA" required="" id="role_TA"> TA (Teaching Assistant) ';
-
-			}
-			else if($_SESSION['user_type'] == "Admin"){
-
+			} else if ($_SESSION['user_type'] == "Admin"){
 			    echo " <input type='radio' name = 'type' value = 'Lecturer' required = '' id='role_lecturer' > Lecturer ";
-
 			}
-
 			?>
-
-			<input type="submit" class="btn btn-primary" value="Create" id="create_btn"><br>
-
+			<br>
+			<button type="submit" class="btn btn-primary" id="create_btn">Create</button>
 			<?php
 
 			error_reporting(E_ALL);
@@ -107,21 +105,9 @@ if ($_SESSION['user_type'] != "Lecturer" && $_SESSION['user_type'] != "Admin") {
 		</div>
 
 
-		<!-- code contributed by Xu Xiaopeng (https://github.com/xxp1999) -->
-		<div id="menu1" class="tab-pane fade" style="margin-top:10px">
-		    <b>Separate two student numbers with a space</b><br>
-		    <form action="batch_insert.php" method="post" id="batch_form">
-			<p>
-			    <textarea cols="70" rows="16" name="users" required=""></textarea>
-			</p>
-			<input type="submit" class="btn btn-primary" value="Register students" id="register_btn"><br>
-		    </form>
-		</div>
+		<div id="tab-existing-accounts" class="tab-pane"><br>
 
-
-		<div id="menu2" class="tab-pane fade"><br>
-
-		    <table class="table-bordered" style="font-size: 10pt;">
+		    <table class="table" style="font-size: 10pt;">
 			<tr style="font-size:10pt;">
 			    <th>ID</th>
 			    <th>Name</th>
@@ -149,13 +135,13 @@ if ($_SESSION['user_type'] != "Lecturer" && $_SESSION['user_type'] != "Admin") {
 
 			while ($row = mysqli_fetch_assoc($result)) {
 			    $pass = $row['Passport_Number'];
-			    $btn = "<button class='btn-warning' onclick=\"updatePass(" . $row['User_ID'] . ",'$pass')\">Reset</button>";
+			    $btn = "<button class='btn btn-warning' onclick=\"updatePass(" . $row['User_ID'] . ",'$pass')\">Reset</button>";
 			    if ($row['Status'] == "Active") {
 				$newstatus = "Blocked";
-				$btnBlock = "<button class='btn-danger' onclick=\"blockUser(" . $row['User_ID'] . ",'$newstatus')\" id=\"block_account_1\">Block</button>";
+				$btnBlock = "<button class='btn btn-danger' onclick=\"blockUser(" . $row['User_ID'] . ",'$newstatus')\" id=\"block_account_1\">Block</button>";
 			    } else {
 				$newstatus = "Active";
-				$btnBlock = "<button class='btn-success' onclick=\"blockUser(" . $row['User_ID'] . ",'$newstatus')\" id=\"activate_account_1\">Activate</button>";
+				$btnBlock = "<button class='btn btn-success' onclick=\"blockUser(" . $row['User_ID'] . ",'$newstatus')\" id=\"activate_account_1\">Activate</button>";
 			    }
 
 			    echo "<tr><td>" . $row['User_ID'] . "</td><td>" . $row['Full_Name'] . "</td><td>" . $row['Email'] . "</td> <td>" . $row['Passport_Number'] . "</td><td>$btn</td><td>$btnBlock</td></tr>";
@@ -170,23 +156,23 @@ if ($_SESSION['user_type'] != "Lecturer" && $_SESSION['user_type'] != "Admin") {
 
 	<div class="col-md-6">
 
-	    <ul class="nav nav-tabs" role="tablist">
+	    <ul class="nav nav-tabs" id="myTab">
 		<li class="nav-item">
-		    <a class="nav-link active" href="#menu3" id="existing_courses">Existing courses</a>
+		    <a class="nav-link active" href="#tab-existing-courses" id="existing_courses">Existing courses</a>
 		</li>
 	    </ul>
 
-            <div id="menu3" class="container tab-pane active"><br>
+            <div id="tab-existing-courses" class="tab-pane active"><br>
 
-		<b> Past courses </b>
-		<hr>
-		<table class="table-bordered" style="font-size: 10pt;">
+		<p class="text-muted"> Past courses </p>
+
+		<table class="table" style="font-size: 10pt;">
 		    <tr>
-			<th>Course Name</th>
+			<th>Course name</th>
 			<th>Faculty</th>
 			<th>Lecturer</th>
 			<th>TAs</th>
-			<th>Assign new TA </th>
+			<th>Assign a new TA </th>
 		    </tr>
 		    <?php
 		    $user_id = $_SESSION['user_id'];
@@ -207,7 +193,7 @@ if ($_SESSION['user_type'] != "Lecturer" && $_SESSION['user_type'] != "Admin") {
 
 			    $ta = "";
 			    while ($rowTA = mysqli_fetch_assoc($resultTA)) {
-				$ta = $ta . "  - " . $rowTA['TA_NAME'];
+				$ta = $ta . "  " . $rowTA['TA_NAME'];
 			    }
 
 			    echo "
@@ -223,7 +209,7 @@ if ($_SESSION['user_type'] != "Lecturer" && $_SESSION['user_type'] != "Admin") {
 				}
 			    }
 
-			    echo "</select>  <input type='hidden' name='assignTA' value='true'> <input type='hidden' name='id' value='$c_id'>  <input type='submit' value='assign' id='assign_btn_$counter'></form> </td></tr>
+			    echo "</select>  <input type='hidden' name='assignTA' value='true'> <input type='hidden' name='id' value='$c_id'>  <button class='btn btn-outline-secondary btn-sm' type='submit' id='assign_btn_$counter'>assign</button></form> </td></tr>
                             ";
 			}
 		    } ?>
@@ -252,4 +238,15 @@ if ($_SESSION['user_type'] != "Lecturer" && $_SESSION['user_type'] != "Admin") {
      }
      window.location.href = "\Script.php\?action=statuschange&uid=" + id + "&status=" + status;
  }
+
+ /* For tabs to work */
+ const triggerTabList = document.querySelectorAll('#myTab a')
+ triggerTabList.forEach(triggerEl => {
+     const tabTrigger = new bootstrap.Tab(triggerEl)
+     triggerEl.addEventListener('click', event => {
+	 event.preventDefault()
+	 tabTrigger.show()
+     })
+ })
+
 </script>
diff --git a/Course.php b/Course.php
index f148f4c..7d054ff 100644
--- a/Course.php
+++ b/Course.php
@@ -86,23 +86,23 @@ if( $_SESSION['user_type'] == "Student")
 	    
 	    <!-- Nav tabs -->
 
-	    <ul class="nav nav-tabs" role="tablist">
+	    <ul class="nav nav-tabs" id="myTab">
 		<li class="nav-item">
-		    <a class="nav-link active" data-toggle="tab" href="#menu1">New</a>
+		    <a class="nav-link active" href="#menu1">New</a>
 		</li>
 		<li class="nav-item">
-		    <a class="nav-link" data-toggle="tab" href="#menu2">Missed</a>
+		    <a class="nav-link" href="#menu2">Missed</a>
 		</li>
 		<li class="nav-item">
-		    <a class="nav-link" data-toggle="tab" href="#menu3">Submitted</a>
+		    <a class="nav-link" href="#menu3">Submitted</a>
 		</li>
 		<li class="nav-item">
-		    <a class="nav-link" data-toggle="tab" href="#menu4">Marked</a>
+		    <a class="nav-link" href="#menu4">Marked</a>
 		</li>
 	    </ul>
 	    
 	    <div class="tab-content">
-		<div id="menu1" class="container tab-pane active"><br>
+		<div id="menu1" class="tab-pane active"><br>
 		    
 		    <?php
 
@@ -138,7 +138,7 @@ if( $_SESSION['user_type'] == "Student")
 		    
 		    if(mysqli_num_rows($result1)==0)
 		    {
-			echo "No active assignments for this course now.";
+			echo "<div class='alert alert-info'>No active assignments now.</div>";
 		    } else {
 			
 			while($row = mysqli_fetch_assoc($result1)) {
@@ -169,7 +169,7 @@ if( $_SESSION['user_type'] == "Student")
 			    echo "<div class='btn btn-default break-word' style='dislay:block; word-wrap: break-word; border-left:4px solid #e6f2ff;'>
                                       <div class='alert alert-warning'>Time left: $days_remaining</div>
   $title ($Marks Marks, $type) <br> <span style='font-size:8pt'> $ins</span>
-   <br> <span style='font-size:10pt'>Posted:$posted &nbsp; Deadline:$deadline   &nbsp; &nbsp;&nbsp;&nbsp; &nbsp;<a href='~\..\SubmitLab.php?id=$labid&url=$url' class='btn-sm btn-info' style='margin-left:50px;'>Submit</a><br> Attachments : $full_link </span>
+   <br> <span style='font-size:10pt'>Posted:$posted &nbsp; Deadline:$deadline   &nbsp; &nbsp;&nbsp;&nbsp; &nbsp;<a href='~\..\SubmitLab.php?id=$labid&url=$url' class='btn btn-sm btn-primary' style='margin-left:50px;'>Submit</a><br> Attachments : $full_link </span>
 </div>";
 			    
 		    }}
@@ -180,7 +180,7 @@ if( $_SESSION['user_type'] == "Student")
 
 
 		
-		<div id="menu2" class="container tab-pane"><br>
+		<div id="menu2" class="tab-pane"><br>
 
 		    <?php
 		    $group_id=$_SESSION['group_id'];
@@ -228,7 +228,7 @@ Lab_Report_ID not in (select Lab_Report_ID from lab_report_submissions where (St
 			    }
 			    ;   
 			    
-			    echo "<div class='btn btn-default break-word' style='dislay:block; word-wrap: break-word; border: 1px solid #F0F0F0;border-left: 4px solid #03407B;'><span class='btn-sm btn-warning' style='margin-left:0px;'>MISSED</span> $title ($marks Marks) <br> <span style='font-size:8pt'> $ins</span>
+			    echo "<div class='btn btn-default break-word' style='dislay:block; word-wrap: break-word; border: 1px solid #F0F0F0;border-left: 4px solid #03407B;'><span class='btn btn-sm btn-outline-danger' style='margin-left:0px;'>MISSED</span> $title ($marks Marks) <br> <span style='font-size:8pt'> $ins</span>
    <br> <span style='font-size:8pt'>Posted: $posted<br> Deadline: $deadline  &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<br> Attachments : $full_link </span>
 </div>";
 			    
@@ -240,7 +240,7 @@ Lab_Report_ID not in (select Lab_Report_ID from lab_report_submissions where (St
 
 
 
-		<div id="menu3" class="container tab-pane"><br>
+		<div id="menu3" class="tab-pane"><br>
 		    <?php
 
 
@@ -275,7 +275,7 @@ Lab_Report_ID not in (select Lab_Report_ID from lab_report_submissions where (St
 			    $id = $row['Lab_Report_ID'];
 			    if( $c_date < $deadline)
 			    {
-				$submittedx="<a  href='~\..\SubmitLab.php?id=$id&url=$url' class='btn-sm btn-info'>Re-submit</a>";
+				$submittedx="<a href='~\..\SubmitLab.php?id=$id&url=$url' class='btn btn-sm btn-light'>Re-submit</a>";
 			    }
 			    
 			    $full_link = "<a href='~\..\Lab_Report_Assignments\\$att1'>$att1</a>";
@@ -360,7 +360,7 @@ where Lab_Report_ID=$lab_repo_id and (lab_report_submissions.Student_id='$studen
 		?>
 
 		
-		<div id="menu4" class="container tab-pane"><br>
+		<div id="menu4" class="tab-pane"><br>
 		    <?php
 		    $resultx  = mysqli_query($con,"SELECT `Submission_ID`, `Submission_Date`, lab_reports_table.`Lab_Report_ID`, `Student_id`, "
 						. "`Course_Group_id`, `Notes`, lab_report_submissions.`Marks`,
@@ -403,7 +403,7 @@ where Lab_Report_ID=$lab_repo_id and (lab_report_submissions.Student_id='$studen
 			if($status=='Marked')
 			{
 			    $rm_data="\Script.php?remarking=yes&id=$Submission_ID&url=$url&status=Remarking";
-			    $remarking="<button  onclick='remarking(\"$rm_data\")' class='btn-sm btn-light'>Request remarking</button>";
+			    $remarking="<button  onclick='remarking(\"$rm_data\")' class='btn btn-sm btn-light'>Request remarking</button>";
 			}
 			if($status=='Remarking')
 			{
@@ -502,7 +502,7 @@ course_groups_table.Course_Group_id=course_group_members_table.Course_Group_id W
 		}
 
 		# Add "delete group" button and allow only group creator to delete it
-		$extra4 = "<button onclick='deleteGroup($id)' class='btn btn-danger' style='height: 25px; width: 95px; line-height: 12px; font-size: 12px'>Delete group</button>";
+		$extra4 = "<button onclick='deleteGroup($id)' class='btn btn-sm btn-danger'>Delete group</button>";
 
 		echo "<div  class='btn-default'><small> $name ($status)  $extra  $extra2  $extra3" . 
 		     (($status == "Created")? "$extra4": "")
@@ -526,7 +526,7 @@ where course_group_members_table.Course_Group_id=$id");
                     #Show group members + remove button next to each member except the creator of the group
                     if($flag){
 			echo "<li>$name - $Student_ID ($status)&nbsp;".(($status != "Created")?"<button onclick='removeMember($Student_ID, $id)'
-                class='btn btn-warning' style='line-height: 12px; font-size: 12px'>Kick out</button>":"")."</li>";
+                class='btn btn-sm btn-warning'>Kick out</button>":"")."</li>";
                     }else{
 			echo "<li><small> $name - $Student_ID ($status)</small>";
                     } 
@@ -689,4 +689,15 @@ where course_group_members_table.Course_Group_id=$id");
      } catch(e){ alert(e); }
  }
 
+
+ /* For tabs to work */
+ const triggerTabList = document.querySelectorAll('#myTab a')
+ triggerTabList.forEach(triggerEl => {
+     const tabTrigger = new bootstrap.Tab(triggerEl)
+     triggerEl.addEventListener('click', event => {
+	 event.preventDefault()
+	 tabTrigger.show()
+     })
+ })
+
 </script>
diff --git a/Courses.php b/Courses.php
index 23fb005..5ca2270 100644
--- a/Courses.php
+++ b/Courses.php
@@ -427,8 +427,8 @@ WHERE  Lecturer_User_ID=$lecturer_id and course_students_table.Status='Pending'"
 		$academic=$row['Academic_Year'];
                 
 		echo "<div class='btn btn-default'>
- $std_name is Requesting to join <br> [($code) - $name ] &nbsp;&nbsp;&nbsp;&nbsp; <br><a href='~\..\Script.php?AcceptStudent=y&id=$id&rs=yes' class='btn-sm btn-success' onclick=return confirm(\"are you sure to join this course?\")' > Accept </a>
- &nbsp;&nbsp;<a href='~\..\Script.php?AcceptStudent=y&id=$id&rs=no' class='btn-sm btn-danger' onclick=return confirm(\"are you sure to join this course?\")' > Decline </a>                     
+ $std_name is Requesting to join <br> [($code) - $name ] &nbsp;&nbsp;&nbsp;&nbsp; <br><a href='~\..\Script.php?AcceptStudent=y&id=$id&rs=yes' class='btn btn-sm btn-success' onclick=return confirm(\"are you sure to join this course?\")' > Accept </a>
+ &nbsp;&nbsp;<a href='~\..\Script.php?AcceptStudent=y&id=$id&rs=no' class='btn btn-sm btn-danger' onclick=return confirm(\"are you sure to join this course?\")' > Decline </a>
 </div>";
                 
             }
@@ -566,7 +566,7 @@ if( $_SESSION['user_type']=="Student")
 			}
 			
 			echo "<div class='btn btn-default' style='word-wrap:break-word'>
-  ($code) $name <br>($url) <br>  <a href='~\..\Script.php?JoinCourse=y&id=$id&std=$student_id&joining=$v' class='btn-sm btn-success' onclick=return confirm(\"Are you sure to join this course?\")' >Join</a>
+  ($code) $name <br>($url) <br>  <a href='~\..\Script.php?JoinCourse=y&id=$id&std=$student_id&joining=$v' class='btn btn-sm btn-success' onclick=return confirm(\"Are you sure to join this course?\")' >Join</a>
    <br> <span style='font-size:10pt'>Faculty: $faculty &nbsp; Year: $academic &nbsp; Lecturer: $lecturer </span><br>$msg</div>
                         ";
 		    }
@@ -606,7 +606,7 @@ INNER JOIN course_students_table on course_students_table.Course_ID=courses_tabl
 		    else
 		    {
 			echo "<div class='btn btn-default'>
-  ($code) - $name  <i class='btn-sm btn-danger'> $Status</i>
+  ($code) - $name  <i class='btn btn-sm btn-danger'> $Status</i>
    <br> <span style='font-size:8pt'>Faculty: $faculty &nbsp; Year: $academic &nbsp; Lecturer: $lecturer </span></div>
                         "; 
 		    }
diff --git a/Header.php b/Header.php
index 95c8f97..129e94b 100644
--- a/Header.php
+++ b/Header.php
@@ -17,10 +17,13 @@ if (mysqli_connect_errno()) {
 <html lang="en-US">
 
     <head>
-	<meta charset="UTF-8">
+	<meta charset="utf-8">
 	<meta name="viewport" content="width=device-width, initial-scale=1">
 	<title>Lab Report Repository</title>
-	<link href="	https://cdnjs.cloudflare.com/ajax/libs/bootstrap/5.0.1/css/bootstrap.min.css" rel="stylesheet" type="text/css" />
+
+	<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.1/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-4bw+/aepP/YC94hEpVNVgiZdgIC5+VKNBQNGCHeKRQN+PtmoHDEXuppvnDJzQIu9" crossorigin="anonymous">
+	<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.1/dist/js/bootstrap.bundle.min.js" integrity="sha384-HwwvtgBNo3bZJJLYd8oVXjrBZt8cqVSpeBNS5n7C8IVInixGAoxmnlMuBnhbgrkm" crossorigin="anonymous"></script>
+
 	<link href="./font-awesome/css/font-awesome.min.css" rel="stylesheet" type="text/css" />
 	<!-- *this css file can be used across all the websites
 	     and any new css class can be added there.
@@ -29,11 +32,8 @@ if (mysqli_connect_errno()) {
 	-->
 	<link href = "./css/main.css" rel="stylesheet" type="text/css" />
 	<script src="./css/jquery.min.js" type="text/javascript"></script>
-	<script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap/5.0.1/js/bootstrap.min.js"></script>
-	<script src=">https://cdnjs.cloudflare.com/ajax/libs/bootstrap/5.0.1/js/bootstrap.bundle.min.js"></script>
 	<script src="./css/jquery.datetimepicker.min.js" type="text/javascript"></script>
 
-
 	<style>
 	 .nav-item {
 	     border-color: #00ff66;
@@ -130,56 +130,60 @@ if (mysqli_connect_errno()) {
 
     <body>
 
-	<nav class="navbar navbar-expand-lg" style="padding-left:150px;padding-right:150px;margin:auto;">
-	    <a class="navbar-brand" href="~\..\index.php"> <img src="logo.png" style="width:30px;height:30px;" alt="LRR Logo"> LRR </a>
-	    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarColor02" aria-controls="navbarColor02" aria-expanded="false" aria-label="Toggle navigation">
-		<span class="navbar-toggler-icon"></span>
-	    </button>
+	<nav class="navbar navbar-expand-lg bg-body-tertiary" style="padding-left:180px;padding-right:150px;margin:auto;">
+	    <div class="container-fluid">
 
-	    <div class="collapse navbar-collapse" id="navbarColor02">
+		<a class="navbar-brand" href="~\..\index.php"> <img src="logo.png" style="width:30px;height:30px;" alt="LRR Logo"> LRR </a>
+
+		<button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarNavAltMarkup" aria-controls="navbarNavAltMarkup" aria-expanded="false" aria-label="Toggle navigation">
+		    <span class="navbar-toggler-icon"></span>
+		</button>
+
+		<div class="collapse navbar-collapse" id="navbarNavAltMarkup">
+		    <div class="navbar-nav">
+
+			<a class="nav-link" href="#">
+			    <?php
+			    if (isset($_SESSION["user_fullname"])) {
+				echo $_SESSION['user_fullname'];
+			    }
+			    ?>
+
+			    &nbsp;
+
+			    <?php
+			    $c_date =  date("Y-m-d H:i");
+			    if (isset($_SESSION['user_student_id']))
+				echo "(" . $_SESSION['user_type'] . " - " . $_SESSION['user_student_id'] . ")   ";
+			    elseif (isset($_SESSION['user_type']))
+				echo "(" . $_SESSION['user_type'] . ")   ";
+			    ?>
+			</a>
 
-		<ul class="navbar-nav mr-auto">
-		    <li class="nav-item active">
 			<?php
 			if (isset($_SESSION["user_fullname"])) {
-			    echo "       <a class='nav-link' href='~\..\Courses.php'><i class='fa fa-book'></i> Courses <span class='sr-only'>(current)</span></a>";
+			    echo "<a class='nav-link' href='~\..\Courses.php'><i class='fa fa-book'></i> My courses </a>";
 			?>
-		    </li>
-		</ul>
 
-		<form class="form-inline my-2 my-lg-0">
-		    Welcome &nbsp;
-		    <b> <?php echo $_SESSION['user_fullname']; ?> </b>
-		    &nbsp;
-
-		    <?php
-		    $c_date =  date("Y-m-d H:i");
-		    if (isset($_SESSION['user_student_id']))
-			echo "(" . $_SESSION['user_type'] . " - " . $_SESSION['user_student_id'] . ")   ";
-		    else
-			echo "(" . $_SESSION['user_type'] . ")   ";
-		    ?>
-
-		    <?php
-		    if ($_SESSION['user_type'] == "Lecturer") { // Show Admin link
-			echo "&nbsp;&nbsp;&nbsp;  <i class=\"fa fa-cog\"> </i>";
-			echo "&nbsp;<a href=\"~\..\Admin.php\" id=\"admin_tab\">Admin</a>";
-		    }
-		    ?>
-
-
-		    &nbsp;&nbsp;&nbsp; <i class="fa fa-user"> </i>
-		    &nbsp;<a href="#" onclick="updatePass(<?php echo $_SESSION['user_id']; ?>)">Update password</a>
-
-
-		    &nbsp;&nbsp;&nbsp; <i class="fa fa-lock"> </i>
-		    &nbsp;<a href="~\..\logout.php">Logout </a>
 
 			<?php
-			}  // Confusing.  What is this for?
+			    if ($_SESSION['user_type'] == "Lecturer") { // Show Admin link
+			        echo "&nbsp;&nbsp;&nbsp;&nbsp;<a class='nav-link' href=\"~\..\Admin.php\" id=\"admin_tab\"><i class='fa fa-cog'></i>Admin</a>";
+			    }
 			?>
-		</form>
 
+			    &nbsp;&nbsp;&nbsp;&nbsp;
+			    <a class="nav-link" href="#" onclick="updatePass(<?php echo $_SESSION['user_id']; ?>)"><i class="fa fa-user"> </i> Update password</a>
+
+			    &nbsp;&nbsp;&nbsp;&nbsp;
+			    <a class="nav-link" href="~\..\logout.php"><i class="fa fa-lock"> </i> Logout</a>
+
+			<?php
+			}  // Closing this conditional test block: if (isset($_SESSION["user_fullname"])) { ...
+			?>
+
+		    </div>
+		</div>
 	    </div>
 	</nav>
 
diff --git a/Submissions.php b/Submissions.php
index 211c9da..f686579 100644
--- a/Submissions.php
+++ b/Submissions.php
@@ -93,26 +93,26 @@ echo "<div class='alert' style='margin-left:20px;border-bottom:2px solid #1D91EF
 
             ?>
 
-            <b>Assignment submissions (<?php echo $count_subs; ?>)</b>
+            <p class="text-muted">Assignment submissions (<?php echo $count_subs; ?>)</p>
             <!-- Nav tabs -->
-            <ul class="nav nav-tabs" role="tablist">
+            <ul class="nav nav-tabs" id="myTab">
                 <li class="nav-item">
-                    <a class="nav-link active" data-toggle="tab" href="#menu1">Unmarked submissions<b> (<?php echo $count_unmarked; ?>)</b></a>
+                    <a class="nav-link active" href="#menu1">Unmarked submissions<b> (<?php echo $count_unmarked; ?>)</b></a>
                 </li>
                 <li class="nav-item">
-                    <a class="nav-link" data-toggle="tab" href="#menu2">Marked submissions <b>(<?php echo $count_marked; ?>)</b></a>
+                    <a class="nav-link" href="#menu2">Marked submissions <b>(<?php echo $count_marked; ?>)</b></a>
                 </li>
 
                 <li class="nav-item">
-                    <a class="nav-link" data-toggle="tab" href="#menu3">Remarking requests <b>(<?php echo $count_remark; ?>)</b></a>
+                    <a class="nav-link" href="#menu3">Remarking requests <b>(<?php echo $count_remark; ?>)</b></a>
                 </li>
 
                 <li class="nav-item">
-                    <a class="nav-link" data-toggle="tab" href="#menu4">Course groups</a>
+                    <a class="nav-link" href="#menu4">Course groups</a>
                 </li>
             </ul>
             <div class="tab-content">
-                <div id="menu1" class="container tab-pane active"><br>
+                <div id="menu1" class="tab-pane active"><br>
 
                     <?php
 
@@ -182,10 +182,10 @@ where Lab_Report_ID=$id and lab_report_submissions.Status='Pending' order by Sub
                                 $full_link = $full_link . " | <a href='~\..\Download.php?file=$att4&attachment=4'>$base_att4</a>";
                             }
 
-                            echo "   <k href='#'>   <div class='btn btn-default break-word' style='dislay:block; word-wrap: break-word; border: 1px solid #F0F0F0;border-left: 4px solid #03407B;'>
+                            echo "<div class='btn btn-default break-word' style='dislay:block; word-wrap: break-word; border: 1px solid #F0F0F0;border-left: 4px solid #03407B;'>
   $title  <br> by: <b> <span class = 'text-selectable'>$submitted_by </span> </b>
-   <br> <span style='font-size:8pt'>Submitted : $posted   <button class='btn-sm btn-info' style='margin-left:50px;' onclick='mark($Submission_ID,\"$title\",$total)'>  Mark</button><br> Attachments : $full_link </span>  
-</div></k>";
+   <br> <span style='font-size:8pt'>Submitted : $posted   <button class='btn btn-sm btn-info' style='margin-left:50px;' onclick='mark($Submission_ID,\"$title\",$total)'>  Mark</button><br> Attachments : $full_link </span>
+</div>";
                         }
                     }
                     echo "";
@@ -193,7 +193,7 @@ where Lab_Report_ID=$id and lab_report_submissions.Status='Pending' order by Sub
 
                 </div>
 
-                <div id="menu2" class="container tab-pane"><br>
+                <div id="menu2" class="tab-pane"><br>
 
                     <?php
 
@@ -217,7 +217,7 @@ where Lab_Report_ID=$id and lab_report_submissions.Status='Marked'  Order by lab
                     }
 
                     if (mysqli_num_rows($result) == 0) {
-                        echo "No Marked submissions for this lab";
+                        echo "No marked submissions.";
                     } else {
 
                         echo "<h3><a href='~\..\Script.php?exportgrade=true&lab=$id&lab_name=$Report_Title'><i class='fa fa-book'></i> Export grades</a></h3>";
@@ -267,10 +267,10 @@ where Lab_Report_ID=$id and lab_report_submissions.Status='Marked'  Order by lab
                             // if you want to use text-selectable class on whole div, just call the css class
 
 
-                            echo "   <k href='#'>   <div class='btn btn-default break-word ' style='dislay:block; word-wrap: break-word; border: 1px solid #F0F0F0;border-left: 4px solid #03407B;'>
+                            echo "<div class='btn btn-default break-word ' style='dislay:block; word-wrap: break-word; border: 1px solid #F0F0F0;border-left: 4px solid #03407B;'>
   $title  <br> by : <b> <span class = 'text-selectable'>$submitted_by </span> &nbsp; &nbsp;&nbsp;&nbsp;&nbsp; [ Marks: $Marks ] </b>  &nbsp; 
-   <hr> Marking notes: $notes<br> <span style='font-size:8pt'>Submitted : $posted        <b>  </b> <button class='btn-sm btn-info' style='margin-left:50px;' onclick='mark($Submission_ID,\"$title\",$total)'>Remark</button><br> Attachments : $full_link </span>  
-</div></k>";
+   <hr> Marking notes: $notes<br> <span style='font-size:8pt'>Submitted : $posted        <b>  </b> <button class='btn btn-light btn-sm' style='margin-left:50px;' onclick='mark($Submission_ID,\"$title\",$total)'>Remark</button><br> Attachments : $full_link </span>
+</div>";
                         }
                     }
                     echo "";
@@ -278,7 +278,7 @@ where Lab_Report_ID=$id and lab_report_submissions.Status='Marked'  Order by lab
 
                 </div>
 
-                <div id="menu3" class="container tab-pane"><br>
+                <div id="menu3" class="tab-pane"><br>
 
                     <?php
 
@@ -349,8 +349,8 @@ where Lab_Report_ID=$id and lab_report_submissions.Status='Remarking'");
                             echo "   <k href='#'>   <div class='btn btn-default break-word ' style='dislay:block; word-wrap: break-word; border: 1px solid #F0F0F0;border-left: 4px solid #03407B;'>
   $title  <br> by : <b> <span class = 'text-selectable'>$submitted_by </span>  &nbsp; &nbsp;&nbsp;&nbsp;&nbsp; [ Marked $Marks ] </b> <br> Remarking Reason : <b>$remarking_reason </b>
    <hr> <span style='font-size:8pt'>Submitted : $posted        <b>  </b> "
-                                . "<button class='btn-sm btn-info' style='margin-left:50px;' onclick='mark($Submission_ID,\"$title\",$total)'>Remark</button>"
-                                . " &nbsp; &nbsp;&nbsp;&nbsp;<a href='~\..\Script.php?ignoreremarking=yes&id=$id&subid=$Submission_ID&header=$header&total=$total&status=Marked' class='btn-sm btn-secondary'>Ignore request</a>"
+                                . "<button class='btn btn-secondary btn-sm' style='margin-left:50px;' onclick='mark($Submission_ID,\"$title\",$total)'>Remark</button>"
+                                . " &nbsp; &nbsp;&nbsp;&nbsp;<a href='~\..\Script.php?ignoreremarking=yes&id=$id&subid=$Submission_ID&header=$header&total=$total&status=Marked' class='btn btn-sm btn-light'>Ignore request</a>"
                                 . "<br> Attachments : $full_link </span>  
 </div></k>";
                         }
@@ -360,7 +360,7 @@ where Lab_Report_ID=$id and lab_report_submissions.Status='Remarking'");
 
                 </div>
 
-                <div id="menu4" class="container tab-pane"><br>
+                <div id="menu4" class="tab-pane"><br>
 
                     <h3>Course groups</h3>
 
@@ -377,10 +377,10 @@ WHERE Course_id=$c_id");
                     } else {
                         while ($row = mysqli_fetch_assoc($result)) {
                             $name = $row['Group_Name'];
-                            $leader = $row['Full_Name'] . "(" . $row['Group_Leader'] . ")";
+                            $leader = $row['Full_Name'] . " (" . $row['Group_Leader'] . ")";
                             $id = $row['Course_Group_id'];
 
-                            echo "<div  class='btn-default'><small> $name -  Leader : $leader </small></div>";
+                            echo "<ul  class='list-group'>$name, Leader: $leader";
 
                             $rs2 = mysqli_query($con, "SELECT `ID`, `Course_Group_id`, course_group_members_table.Student_ID, 
                             course_group_members_table.`Status`,users_table.Full_Name FROM `course_group_members_table` 
@@ -393,8 +393,9 @@ where course_group_members_table.Course_Group_id=$id");
                                 $status = $row['Status'];
                                 $Student_ID = $row['Student_ID'];
 
-                                echo "<li><small> $name-$Student_ID ($status)</small></li>";
+                                echo "<li class='list-group-item'>$name ($Student_ID) - $status</li>";
                             }
+			    echo "</ul><br>";
                         }
                     }
                     ?>
@@ -450,4 +451,14 @@ where course_group_members_table.Course_Group_id=$id");
         }
     }
 
+ /* For tabs to work */
+ const triggerTabList = document.querySelectorAll('#myTab a')
+ triggerTabList.forEach(triggerEl => {
+     const tabTrigger = new bootstrap.Tab(triggerEl)
+     triggerEl.addEventListener('click', event => {
+	 event.preventDefault()
+	 tabTrigger.show()
+     })
+ })
+
 </script>
diff --git a/index.php b/index.php
index 3a08d99..da2bd49 100644
--- a/index.php
+++ b/index.php
@@ -7,8 +7,7 @@ session_start();
 <?php
 // if the user has already logged in, then clicking the LRRS icon should not display the login page (i.e., index.php).
 if (isset($_SESSION["user_fullname"])) {
-    echo  '<div class="alert alert-info"> You\'ve already logged in.</div>';
-    header("Location: Courses.php");
+    echo  '<div class="container alert alert-info"> You\'ve already logged in.</div>';
     exit();
 }
 ?>