if($mech->mirror("url","$filename") == RC_NOT_MODIFIED ) {
                print " link not Updated \n\n\n";
                if($mech->response()->is_success){
                        print " response is success\n\n";
                        print " content :",$mech->response()->as_string,"\n\n";
                }
                else {
                        print "failure \n\n";
                }
 }
 else {
     print " link updated...\n\n";
     $mech->save_content($filename);
 }