Parameters take the form of
'somename=value&othername=value&...'
they are received by the URL procedure, when the link is clicked. (ie only the actual request). Remember a browse of form is an Event Handler, not a "procedure" so the parameter only exists for the life of the _event_.
If you want to use a parameter for more events then store it in the session queue;
p_web.StoreValue('someName')
Then you can use it as a SessionValue in your procedure.
cheers
Bruce