Untitled

<?php
var_dump( $_POST);
    function Login($user,$pass){
        if($user != "biggun"|| $pass != "boom"){
            return false;
        }else{
            return true;
        }
    }
    if(!empty($_POST)){
        $user = $_POST['user'];
        $pass = $_POST['pass'];

        if(Login($user, $pass)===true){
            $salt = "kill";
            $cookieVal = $user . "," . md5($user.$salt);
            setcookie("loggedin", $cookieVal,time()+60*60*24*30); //1maand
           header('Location: index.php');
        } else{
            $error = true;
        }
    }
?>


<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <link rel="stylesheet" href="css.css">
</head>
<body>

<div id="app">
    <form action="" method="post">
    <h1>Log in to Twitch</h1>
    <nav class="nav--login">
        <a href="#" id="tabLogin">Log in</a>
        <a href="#" id="tabSignIn">Sign up</a>
    </nav>

  <?php if( isset($error) ): ?>
    <div class="alert hidden">That password was incorrect. Please try again</div>
  <?php endif; ?>

  <div class="form form--login">

            <label for="username">Username</label>
            <input type="text" id="username" name="user">

            <label for="password">Password</label>
            <input type="password" id="password" name="pass">

  </div>

  <div class="form form--signup hidden">
    <label for="username2">Username</label>
    <input type="text" id="username2">

    <label for="password2">Password</label>
    <input type="password" id="password2">

    <label for="email">Email</label>
    <input type="text" id="email">
  </div>

  <a href="#" class="btn" id="btnSubmit">Log In</a>
  </form>
</div>
</body>
</html>