I'm not even sure where to set a run time value for a filter variable - where do I do that? Now, even with the new code you sent, I'm getting a different error message. Please see attached file. The message is:
Warning: mysql_select_db() expects parameter 2 to be resource, object given in C:\wamp\www\2010 new site\delete_user2.php on line 53
Warning: mysql_query() expects parameter 2 to be resource, object given in C:\wamp\www\2010 new site\delete_user2.php on line 55