when you get to the clients_Detail.php successfully, what is the quesrystring variable name?
add that into the redirect code:
WA_Auth_RestrictAccess("clients_Detail.php?quesrystringvarname=.isset($_GET['quesrystringvarname'])?$_GET['quesrystringvarname']:""."");
substitute "quesrystringvarname" with the correct name for the quesrystring variable