Session Variables ~ Best Practices

I'm right in the middle of developing some pages that will require session cookies. Now I have a few questions and hope I don't bore you too much... I presume I am right in assuming that I can declare variables anywhere I like providing I have started a session on the page but I cannot actually use those variables until a post or some similar action has been performed by the user. I am also wondering if I need to declare all my variables one after the other or can I simply declare variables that I will be using immediately upon submission. -- ----------------------------- Michael Mason Arras People www.arraspeople.co.uk -----------------------------