PHP实现类似js中alert()提示框

/**

 * 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();

    }

}