<?php
$user = $_POST['user'];
$pass = $_POST['pass'];
if($user == "admin"
&& $pass == "admin")
{
include("secure.html");
}
else
{
if(isset($_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>
<?}
}
?>