try session registering them.
at the top of the page(for safety sake, try using a different name from the original variable, i prefix with "live_":
session_start();
session_register("live_item");
session_register("live_vendor");
then set the variable in usual manner
$item = $whatever;
$vendor= $again_whatever;
link as normal
<A HREF="check.php">Check</A>
on check.php
$item=$live_item;
$vendor=$live_vendor;
To be absolutley safe, session_unregister them when you have dealt with the information.
Hope this helps
Kevin