How do i link html directory that is outside iframe?

Hi
I got a login system on my site. The php based login system is working in an iframe. All works fine but when i click the login i come to a php in the iframe that only says you are logged in. But i want the php iframe to open a html page outside the iframe when i log in.

How do i do that?

Thanks for help

 

<a href="login.php" target="_top">
<form method="post" action="login.php" target="_top">