Update line 26 to:
$WAFV_Redirect = "index.php?invalid=1&LodgeID=". ((isset($_POST["LodgeID"]))?$_POST["LodgeID"]:"") ."";
That will add the invalid $GET variable when the validation fails and trigger the repopulating of the other form elements.
You have a misplaced </div> tag on line 275... that might be causing the file fields to not validate properly with jquery.