i have problem with my index id for class_student.php.. i not sure where it missing smth.. kindly look it for me. there is an error with index id at line 3 which mean $get_id = $_GET['id'];
<?php include ('session.php'); ?>
<?php
$get_id = $_GET['id'];
include('header.php');
$user_query = mysql_query("select * from student where student_id='$session_id'") or die(mysql_error());
$user_row = mysql_fetch_array($user_query);
?>
<?php
$query_class = mysql_query("select * from class where class_id='$get_id'") or die(mysql_error());
$row_class = mysql_fetch_array($query_class);
$teacher_id = $row_class['teacher_id'];
$teacher_query=mysql_query("select *from teacher where teacher_id='$teacher_id'")or die(mysql_error());
$teacher_row= mysql_fetch_array($teacher_query);
?>
<body>
<?php include('navhead_student.php'); ?>
<div class="container">
<div class="row-fluid">
<div class="span3">
<div class="hero-unit-3">
<div class="alert-index alert-success">
<i class="icon-calendar icon-large"></i>
<?php
$Today = date('y:m:d');
$new = date('l, F d, Y', strtotime($Today));
echo $new;
?>
</div>
</div>
<div class="hero-unit-1">
<ul class="nav nav-pills nav-stacked">
<li class="nav-header">Links</li>
<li>
<a href="student_home.php"><i class="icon-home icon-large"></i> Home
<div class="pull-right">
<i class="icon-double-angle-right icon-large"></i>
</div>
</a>
</li>
<li class="active">
<a href="student_class.php"><i class="icon-group icon-large"></i> Class
<div class="pull-right">
<i class="icon-double-angle-right icon-large"></i>
</div>
</a></li>
</ul>
</div>
</div>
<div class="span9">
<a href="student_class.php" class="btn btn-success"><i class="icon-arrow-left"></i> Back</a>
<br><br>
<div class="alert">Class:<a href="" > <strong><?php echo $row_class['course_id']; ?></strong></a>
Subject:<a href=""> <strong><?php echo $row_class['subject_id']; ?></strong></a>
Teacher::<a href=""> <strong><?php echo $teacher_row['firstname']." ".$teacher_row['lastname']; ?></strong></a>
</div>
<div class="hero-unit-3">
<table cellpadding="0" cellspacing="0" border="0" class="table table-striped table-bordered" id="example">
<div class="alert alert-info">
<button type="button" class="close" data-dismiss="alert">×</button>
<strong><i class="icon-user icon-large"></i> Files</strong>
</div>
<thead>
<tr>
<th>File Name</th>
<th>Description</th>
<th>Date Uploaded</th>
<th>Action</th>
</tr>
</thead>
<tbody>
<?php
$query = mysql_query("select * from files where class_id = '$get_id'") or die(mysql_error());
while ($row = mysql_fetch_array($query)) {
$file_id = $row['file_id'];
?>
<tr class="odd gradeX">
<!-- script -->
<script type="text/javascript">
$(document).ready(function(){
$('#d<?php echo $file_id; ?>').tooltip('show')
$('#d<?php echo $file_id; ?>').tooltip('hide')
});
</script>
<!-- end script -->
<td><?php echo $row['fname'] ?></td>
<td><?php echo $row['fdesc']; ?></td>
<td><?php echo $row['fdatein']; ?></td>
<td width="50">
<a href="<?php echo $row['floc']; ?>" rel="tooltip" title="Download File" id="d<?php echo $file_id; ?>" role="button" data-toggle="modal" class="btn btn-info"><i class="icon-download-alt icon-large"></i></a>
</td>
</tr>
<?php } ?>
</tbody>
</table>
<!-- end slider -->
</div>
</div>
</div>
<?php include('footer.php'); ?>
</div>
</div>
</div>
</body>
</html>