Pop Up A Window When Logged In Successfully…

I have a client who needs a pop-up-window with the url of his chat to load once and only once during the login. I thought this would be easy and it seems to be having problems. Maybe somebody can help?

function popupchat() {

?>

<SCRIPT LANGUAGE="javascript">

<!--

window.open ('http://languageconnectsus.gixawchat.com/')

-->

</SCRIPT>

<?php

}

add_action('wp_login ', 'popupchat');

Added that as a file in mu-plugins and it doesn’t work. Any suggestions?