Clean up code on joomla site relating to sessions

I am not a developer but I have been playing around with a joomla build and need someone to clean up something I've written. I am trying to store a code into a session variable from a form, it works but I have to submit the for 3 times for it to work? I need a little help to get this working smoothly, I know it's not a big job but I will want to do more to this site in the future. Link to page this relates to is [login to view URL] use 42 as the code and submit the form, like I said you will have to do this several times which is what I want to fix once the session is active the images under form will change. Thanks for your help