<?
$pass=htmlspecialchars(mysql_real_escape_string(trim($_POST['pass'])));
$login=htmlspecialchars(mysql_real_escape_string(trim($_POST['login'])));
if($pass==ADM_PASS && $login==ADM_LOGIN){
$_SESSION['adm']="1";
header("Location: index.php");
}
echo '<form method="POST" action="?">
Лoгин:<br>
<input type="text" name="login"><br>
Пороль:<br>
<input type="password" name="pass"><br>
<input type="submit" value="Войти">
</form>';
?>