Moving multiple items one at a time while using session variables

[Xandler]

Alright, I'm new to this and am wondering how this can be done...I managed to figure out how to move singular items to a different page. What I want to do is when a user clicks a button it moves the selected item to a different page (while saving the session variable on that page so it doesn't reset (unsure as to how)), then the user can go back to the page with the products and add more (without the information on the "order form" resetting back to nothing as it were), I've looked into session variables and just can't find the answer I'm looking for. Any help would be greatly appreciated!

Thank you,

Xandler