so basically your page is relying on the subcatID=6&itemTypeID=1 query string variables?
you can add those into the redirect so they are passed when the page is redirected:
$WA_redirectURL = "?sent=true".((isset($_GET['subcatID']))?"&subcatID=".$_GET['subcatID']:"")."".((isset($_GET['itemTypeID']))?"&itemTypeID=".$_GET['itemTypeID']:"")."";