<?php

    require_once 'conn.php';

    $con = @new mysqli($host,$db_login,$db_pass,$db_name);

    if($con->connect_errno!=0)
    {
        echo "Can't connect to database: ".$con->connect_errno." Desc: ".$con->connect_error;
    }
    else
    {
        $username = htmlentities($_POST['login']);
        $password = htmlentities($_POST['password']);

        $res = mysqli_query($con,"SELECT * FROM users WHERE '$username'=login AND '$password'=pass");
        if(mysqli_num_rows($res)==0)
        {
            header('Location: index.php');
        }
        else
        {
            echo Zalogowano!
        }

    }
?>