function processLogout( )
{
   var url   = '/system_ajax.php?class=system&function=logoff&'+ajaxRand;
   var myReq = loadXMLDocSync( url, 'processLogoffResponse' );
}

function processLogoffResponse( reqId )
{
   if ( req[reqId].readyState == 4 )
	{
		// only if "OK"
		if ( req[reqId].status == 200 )
		{
			window.location.replace( '/login' );
      }
	}
}