that should be working, to troubleshoot, find the following line of code:
$WA_redirectURL = "listing_Detail.php";
and change it to:
//$WA_redirectURL = "listing_Detail.php";
$WA_redirectURL = "";
then on the bindings panel, expand the WA Uploaded Files Global Status and drag the Debug info binding to the page.
post back the results of the debug info after trying to upload again.