About the form action. Either way works fine, so it was fine before.
The second thing... I suggest you use if(isset()) instead of just if() like this:
I also suggest you using up-to-date methods for sessions! session_register and session_unregister are long depreciated. Read the manual for more info.
But, I believe your problem is here: you are not using superglobals. _POST variables and _SESSION variables are superglobals. For example, you seem to be getting the variable $userid from nowhere - use $_POST['userid'] instead, because you are passing values from the first page to the next page with the POST method.
Where will you be in 100 years?
Try new FreshView 0.2!