網頁無法自動跳轉，代碼如下，跪求大神回答?。。。。?/h1>

<title>用戶驗證</title>
<?php
	session_start();
	$user=trim($_POST['user']);
	$pass=trim($_POST['pass']);
	if($user=="admin"&&$pass="admin"){
		echo?"登錄成功";
		$_SESSION['user']=$user;
		$_SESSION['pass']=$pass;
		$_SESSION['producelist']="";
		$_SESSION['quatity']=""?;?//初始化購物車內沒有商品
		echo?"<meta?http-equiv=\"refresh\"?conten=\"3;url=books.php\">3秒轉入主頁，wait";//此行代碼為什么不能自動跳轉到books.php
	}else{
		echo?"<script>alert('登錄失敗');history.back();</script>";
	}
?>