ha ha - well I've got Stu well trained <g>.
But "normal Clarion" doesn't go away, as long as you're on the same thread - and that's the key - being on the same thread.
So a block of code runs, as always, from top to bottom. Anything you do inside that block is good. Procedure calls, file buffers, it's all ok.
However _IF_ you want to use something in some other block of code, for example when the form opens you prime something, then do something with it when the form closes, well, there Session values are important because (and this is the really important bit to grasp) those two "actions" occur on different threads. A windows program puts all the Form interaction on one thread, the web doesn't.
Cheers
Bruce