/**  * JS提示跳转  * @param  $tip  弹窗口提示信息(为空没有提示)  * @param  $type 设置类型 close = 关闭 ，back=返回 ，refresh=提示重载，jump提示并跳转url  * @param  $url  跳转url  */ function alert($tip = "", $type = "", $url = "") {     $js = "<script>";     if ($tip)         $js .= "alert('" . $tip . "');";     switch ($type) {         case "close" : //关闭页面             $js .= "window.close();";             break;         case "back" : //返回             $js .= "history.back(-1);";             break;         case "refresh" : //刷新             $js .= "parent.location.reload();";             break;         case "top" : //框架退出             if ($url)                 $js .= "top.location.href='" . $url . "';";             break;         case "jump" : //跳转             if ($url)                 $js .= "window.location.href='" . $url . "';";             break;         default :             break;     }     $js .= "</script>";     echo $js;     if ($type) {         exit();     } }