[RESOLVED] what's wrong hare

[r_amin]

<?
session_start();

//if Null T1 and T2
if((!$T1) || (!$T2)){
echo  "<div id=\"Login_message\" style=\"color:red\">Invalid User or Password!</div>";
include ('index.html');
exit;
}

?>

it returns

Invalid User or Password!
"; include ('index.html'); exit; } else echo aaa; ?>

why it returns the last line?
Please Help