Return to Previous Page from Shopping Cart

I am having a problem getting back to the correct page once I “view cart”. We use the Zen shopping cart. I have tried setting Session variables and also setting a returnPage cookie. In each case the page id is incremented and I am returned to the wrong page. Seems like Zen really screws around with SESSION variables so I can’t get them back the way they were set to start with.

Setting a cookie:

$dateToExpire = time() + 720;

	$page_id     = get_queried_object_id();
	$return_page =  "https://www.myserver.com/?p=" . $page_id;

	setcookie("ReturnPage", $return_page,$dateToExpire, "/", "myserver.com");

This is executed each time a page that contains a purchasable item is accessed so I can grab the page id, slap it in a cookie and retrieve it later when coming back from the shopping cart. My problem is $page_id keeps getting incremented between returning from the shopping cart and recovering the COOKIE value.

any thoughts would be appreciated.

G.