Variable passing through a form

Hi, I currently have a page divided into three areas, two of which are iframes. The user selects a component out of part 1, which decides what is shown in part 2. When something is clicked in part 2 the information updates in the second iframe, or part 3. This is all working fine through $PHP_SELF and target. I am now working in part 3 of my page which has already had variables passed to it from part 2, however when I try to make selections on this page which should update in the same area ($PHP_SELF) I am losing all the variables which were earlier passed. I have tried $REQUEST_URI also which didn't help. example: after coming from part 2 $REQUEST_URI might be test.php?var1=a&var5=f&var16=d . If I then select and option on this new form and then send it to itself I lose everything that was originally there (output might then be test.php?newvar=new) The line which executes my form is (currently) <form name="tick" action="<?php echo $REQUEST_URI; ?>" method="get" enctype="multipart/form-data"> , and as I said $REQUEST_IRI does contain the variables on initial loading. I need to keep these initial variables and add the new (ie test.php?var1=a&var5=f&var16=d&newvar=new) Please help! Thanks, Michael.