使用Ajax登录Php

我正在尝试使用ajax登录，我希望用户登录，如果用户名（电子邮件）和密码正确，页面应该使用.load方法加载页面"perfil.php"，我不会发布代码，因为它不相关。然而，即使我键入随机用户/密码，也不会发生任何事情。

我刚开始使用SESSION和AJAX，所以任何帮助都将不胜感激，顺便说一句，我现在不需要关于哈希密码的答案。

指数

<?php
    session_start();
    if(!empty($_SESSION['login_user'])){
        header('Location: user/perfil.php');
    }
?>
<form class="form-signin" id="form-signin" method="post" action="">
<h2 class="form-signin-heading">Sign in</h2>
<input type="email" name="email" id="inputEmail" class="form-control" placeholder="Email address" required="true" autofocus="true">
<input type="password" name="password" id="inputPassword" class="form-control" placeholder="Password" required="true">
<div class="checkbox">
    <label>
        <input type="checkbox" value="remember-me"> Lembrar-me
    </label>
</div>
<button id="entrar" class="btn btn-lg btn-primary btn-block" type="submit" name="submit">Sign in</button>

login.php

<?php
include_once '../config/db.php';
session_start();
if (isSet($_POST['email']) && isSet($_POST['password'])) {
    try {
        $pdo = Database::connect();
        $email = $_POST['email'];
        $password = $_POST['password'];
        $query= "SELECT id FROM utilizador WHERE email = '$email' and pass = '$password'";
        $stmt = $pdo->prepare($query);
        $stmt->execute();  
        $num=$stmt->rowCount();
        $row = $stmt->fetch(PDO::FETCH_ASSOC);
        if($num > 0)
            $_SESSION['login_user']=$row['id'];
            echo $row['id'];    
        }
        Database::disconnect();
    }
    catch (Exception $e){
        echo 'Exception: ',  $e->getMessage(), "'n";
    }
}
?>

javascript

$('#entrar').click(function()
{
    var email = $("#inputEmail").val();
    var password = $("#inputPassword").val();
    var dataString = 'email='+email+'&password='+password;
    if($.trim(username).length>0 && $.trim(password).length>0)
    {
        $.ajax({
            type: "POST",
            url: "user/login.php",
            data: dataString,
            cache: false,
            beforeSend: function(){ $("#entrar").val('A entrar...');},
            success: function(data){
                if(data)
                {
                    showNotas();
                    $('#form-signin').fadeOut('slow', function(){
                        $("#section-1 .container").load("user/perfil.php").fadeIn(1500).delay(5000);
                        $("#section-1 span").text("Perfil");
                    });
                    $('#notas').show();
                }
                else
                {
                    $("#entrar").val('Sign in')
                    $("#error").html("<span style='color:#cc0000'>Error:</span> Invalid username and password. ");
                }
            }
        }); 
    }
return false;
});

编辑：Chrome开发没有显示任何错误