php js 跳轉不了是為什麼阿

php

function alert_go($msg,$url){    echo "";}$username=$_POST['username'];$pass=$_POST['pass'];$pass2=$_POST['pass2'];$email=$_POST['email'];if(!filled_out($_POST)){    echo "資訊不全，不能錄入！";    exit;}if(!valid_email($email)){    echo "郵箱格式不正確，請重新檢查!";    exit;}if($pass != $pass2){    echo "兩次密碼不一致,請重新輸入";    exit;}if((strlen($pass)<6) || (strlen($pass)>16)){    echo "密碼長度不正確，請重新輸入";    exit;}//echo "註冊成功"; @ $db=new mysqli('localhost','root','020310','demo'); if(mysqli_connect_errno()) {    echo "資料庫連接錯誤，請檢查後重新串連";    exit; } $query="insert into user(username,password,email) values(?,?,?)"; $stmt=$db->prepare($query); $stmt->bind_param('sss',$username,$pass,$email); $ss=$stmt->execute(); if($ss) {    alert_go('註冊成功!','http://baidu.com');    //header('Location: http://localhost/login/login.html'); }else{    alert_go('註冊失敗！','http://baidu.com'); } 為什麼最後跳轉不到百度頁面啊

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