我被拒绝访问并且链接到服务器无法建立错误

Question

我被拒绝访问并且无法建立到服务器的链接错误。这是我的代码，你能解释一下我的错误吗？

<?php

session_start ();
include("includes/db.php");

if(isset($_POST['login'])) {
    $email = mysql_real_escape_string($_POST['email']);
    $pass = mysql_real_escape_string($_POST['pass']);
    $sel_user = "select * from admins where user_email='$email' AND user_pass='$pass'";
    $run_user = mysqli_query($con, $sel_user);
    $check_user = mysqli_num_rows($run_user);
}