Help with submitting records into a database.

Hi everyone, Im looking for a bit of help concerning a php problem ive stumbled upon.

Scenario: For my final year project at uni I have to create an online attendance register system using PHP & MySQL which allows a lecturer to;

1) login ->
2) view the modules they teach (modules.php)->
3) view a list of timetabled sessions for the chosen module (Labs, Tutorials, Lectures etc...) (session.php)->
4) view a class list for the chosen session, containing a list of all the students timetabled for the session (student_session.php) -->
5)submit a form which inserts the relevant values (student_id, session_id, week_no, attendance[0 or 1]) into a 'student_session' table.

Problem:So far I have completed tasks 1-4 without any problems, however I am considerably stuck on task 5.

Below is the relevant part of 'student_session.php', which displays a new row for every timetabled student, along with a check box to mark their attendance, and then passes it onto the form handler (submit_attendance.php)

<?php	
		include ('./includes/db_connect.php');
										
					$query  = 
					"SELECT  CONCAT_WS(' ',student.first_name, student.last_name) AS name, student.student_id, student.course_id, module.module_id, module.course_id
					FROM	student, module
					WHERE student.course_id = module.course_id 
					AND module.module_id = '{$_SESSION['module_id']}'
					ORDER BY name ASC ";
								
					$result = mysql_query($query);
					$num = mysql_num_rows($result);					

					// If it ran OK, display the records.
					if ($num > 0) 
					
					{ 
						echo 
							"<p>There are <strong>$num</strong> students timetabled to attend this session.</p>\n"
							
						;
						

						// Table header.
						echo 
							'<form method="post" action="submit_attendance.php">
							<table class="modules" align="left" cellspacing="0" cellpadding="5" >
								<tr>
									<td class="moduletitle" colspan="2">Tick the box to record a students attendance</td>
								</tr>
						
								<tr class="hover">
									<td class="module" align="left"><b>Name</b></td>
									<td class="module" align="left"><b>Present</b></td>
								</tr>'
						;
					// Fetch and print all the records.
					while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) 
					
						{
							echo 
								'<tr class="module" align="left">
									<td class="module" align="left">
										<a href="./student_details.php? student_id=' . $row['student_id'] .'">' . $row['name'] .'</a>
										<input type="hidden" name="student[]"  />
									</td>
									
									<td class="module" align="left">
										

											<input type="checkbox" name="attendance[]" value="1" >
												<img src="./images/green_tick.png" width="12px" height="12px"/>
											<br>
										
									</td>
									
										
								</tr>';
							
						}
							echo 
								'<tr>
									<td>
									
									<input type="submit" class="submit"  name="submit" value="Submit" />
									<input type="hidden" name="submitted" value="TRUE" />
									</td>
								</tr>
								</table></form><br/>'
							;
							
					// Free up the resources.						
					mysql_free_result ($result); 

					} 
					
					else // If it did not run OK.
					{ 
						echo
							'<p class="error">No students are timetabled to attend this session.</p>'
						;
					}
		
				
					?>

Code (markup):

submit_attendance.php - This is where the problem occurs, the desired result would be to enter the values of the $_SESSION['session_id'] and $_SESSION['week_no'] (to represent the teaching session: for later use to generate reports)
and then the names of every student who was present.
However all it does at present is enter one row into the 'student_session' table with null values for all fields except a '1' in the 'attendance' field.

		<?php
			session_start();
		
						include ('./includes/db_connect.php');													
					
					
					
					
					if (isset($_POST['submitted'])) { // Check if the form has been submitted.
					
					
					$a = isset( $_POST['attendance'] ) ? 1 : 0;
	
	
		if (isset($_POST['student'])) {
			$student = escape_data($_POST['student']);
		} else {
			$student = NULL;
		}

		if (isset($_SESSION['week_id'])) {
			$week = escape_data($_SESSION['week_id']);
		} else {
			$week = NULL;
		}
		
		if (isset($_SESSION['session_id'])) {
			$sess = escape_data($_SESSION['session_id']);
		} else {
			$sess = NULL;
		}

	
			
		
		}
		
		if ($a && $student && $week && $sess) { // If everything's OK.
	
		// Add the student_session to the database.
		$query = "INSERT INTO student_session (attendance, student_id, week_id, session_id) VALUES ('$a', '$student', '$week', '$sess')";
		if ($result = mysql_query ($query)) { // Worked.
			echo '<p>The attendance has been recorded.</p>';
		} else { // If the query did not run OK.
			echo '<p><font color="red">Your submission could not be processed due to a system error.</font></p>'; 
		}
		
		}
	

	
	?>

Code (markup):

I know im nearly there, and im more than certain its just a case of a missing for loop or an array,
sadly im more of a front end developer and I would really appreciate it if some kind PHP/MySQL guru would give me a hint or a push in the right direction.

Thanks in advance - Dan

 

print out the query before you run it
also do a print_r on $_SESSION and $_POST to make sure those values are as you expect

my guess is that if you do this the problem will be easy to spot