scusate la domanda stupida

codice:
if($user != ""){
	mysql_select_db($database_conn, $conn);
	$query = "SELECT * FROM clienti WHERE user='$user' AND password='$password'";
	$Login = mysql_query($query, $conn) or die(mysql_error());
	$row_result = mysql_fetch_assoc($Login);
	$totalRows_result = mysql_num_rows($Login);
	$id = $row_result['ID'];
	if(mysql_num_rows($Login)) {
	$_SESSION['username'] = $user; 
	header("Location: autenticato.php?id=$id"); 
	exit;
	}else{
	 $risp = "ERROR! $id";  
	}
}