调试一些PHP代码

我正在尝试使用angularjs和PHP进行登录。但碰到问题我不明白为什么？

<?php
date_default_timezone_set("Asia/Bangkok");
session_start();
$data = json_decode(file_get_contents("php://input"));
$email = mysql_real_escape_string($data->email);
$password = mysql_real_escape_string($data->password);
{
    $con=mysqli_connect("localhost","root","thanh03021986","erp");
    if (mysqli_connect_errno()){
        echo "Failed to connect to MySQL: " . mysqli_connect_error();
    }   
    $query = mysqli_query($con,"SELECT email, password FROM user WHERE email = '$email'"); 
    $numrow = mysqli_num_rows($query); 
    if($numrow > 0){    
        while($rows = mysqli_fetch_array($query))
        {
                $dbemail = $rows['email'];
                $dbpassword = $rows['password'];            
        }
        $con->close();
        if($email==$dbemail && $password == $dbpassword){
            $_SESSION['uid'] = $email;
            header('location:/A.php');
        }       
    }
}
?>

当If()返回true时，$_SESSION['uid'] = $email工作，但header('location:/A.php');不工作。我试着把header('location:/A.php');从IF()中去掉，头工作吗？？？请帮忙解释一下？