restricting access to a test after certian number of attemps

[webguync]

Here is my situation. I have an exam application built in Flash, where after the taker is finished and submits their scores a record is created in MySQL in a log table. Basically there is a column called attempt which is populated with a 1 after they have successfully finished the exam. When this column has a 1, the user is locked out and cannot access the exam when they try and login. The Flash part was built a while back in AS3 and is very cumbersome to try and figure out and make changes, so I have been trying to improve some things on the PHP/MySQL end. What I have now is a php based login which uses if else statements to determine if a user has passed and if they have not uses a DELETE statement to delete their log record and thus they regain access to taking the exam. Code below.

<?php

   if(($pcnt[$i]*100) > 89)
   {
      echo "<span class='green'>you did great!</span>";
   }
   else
   {
     $query_delete = "DELETE FROM log_March2011
USING log_March2011 INNER JOIN roster_March2011
WHERE log_March2011.user_id =roster_March2011.user_id
AND roster_March2011.user_id = '{$_SESSION['user_id']}'"; 
//echo $query_delete; //for debugging test
$result_delete = mysql_query($query_delete) or trigger_error('Query failed: ' .mysql_error());
//$num = mysql_affected_rows($db);
if ($result_delete)
{
echo "<span class='red'>Please review missed questions/sections below</span><br />You can now retake the exam";
}// end if
else
{
echo "No record of taking exam";
} //end else
   }
?>

 

what I would like to do to improve the application is to be able to implement a set number of attempts allowed before the user is disallowed to take the exam again, but not sure how to implement this or is even possible?