Oracle Forms

Hello,
I am very green to Oracle forms builder. I have a multi-form application that I am trying to create a parameter list for on the first form and pass that parameter to a second form via the OPEN_FORM method. I am able to create the parameter, I set a runtime breakpoint and ran the form and verified that the correct value is there. I can then call the second form using the CALL_FORM('form_name',ACTIVATE,NO-HIDE,'params_list_name'). Once the second form pulls up how do I verify that the parameter is indeed there and how do I access that parameter.

The project I am working on is a simple log in screen where a user would enter his or her ID and Password/Pin, this is the first form. The trigger on the "log in" button verifies that the user entered the correct information and calls the next form. I am assuming that passing a parameters list is the most effecient way to do this. I would like to pass the UserID to the second form and use it in the WHERE clause of a SQL expression in order to show the user his or her personal data. Do I need to create a PRE_FORM trigger on the second form to accept the passed parameters list?

Any help would be much appreciated.

Alex