If you look at the code for this forum it does this very thing from the profile pop up window and other places for things like opening the email messanger, or to PM a user. The JavaScript function I wrote to do this is:-
<script language="JavaScript">
//Function to open email messenger
function openInMainWin(winLocation){
window.opener.location.href = winLocation
window.opener.focus();
window.close();
}
</script>
I then reference it form a link using the following code:-
javascript:openInMainWin('email_messenger.asp')