how to keep previous session values

Hi all

I have a JCo program

teh values in the selecton screen initialized from a function module which is executed in doInitialization() for the loginID for the user logon on the portal but the user can change any of the values.

When the user click on the submit button and there is no output it catchs the exception and stay in the selection screen. but the problem is that it re-initialize the values again and I want to keep the previous values (since the user may changed any of the values as I mentioned).

Also. when it display the result and the user click Back button it tdoes the same thing and I do not want that.

Any idea how to keep pld values?

Thanx