PHP: Simple password protected page with md5 (found on: https://stackoverflow.com/questions/4115719/easy-way-to-password-protect-php-page)

secure.php

<?php
$user = $_POST['user'];
$pass = md5($_POST['pass']);
$hash = "enter your md5 hash here";

if($user == "admin"
&& $pass == $hash)
{
        echo "Secure content:";
        include("content.html");
}
else
{
    if(isset($_POST))
    {?>

            <form method="POST" action="secure.php">
            User <input type="text" name="user"></input><br/>
            Pass <input type="password" name="pass"></input><br/>
            <input type="submit" name="submit" value="Go"></input>
            </form>
    <?}
}
?>

Maybe not to use md5 without adding text (salt)?
Or even better to use md55