[HTML building some tables and the top-of-page navigation]

<SCRIPT TYPE="text/javascript" LANGUAGE="JavaScript">
function fill_in_screensize() {
     document.forms['login_form'].screen_width.value=screen.width;
     document.forms['login_form'].screen_height.value=screen.height;
     return true;
}
</SCRIPT>

<FORM name=login_form ACTION=[ACTION] METHOD=[METHOD]
<input type=hidden name=screen_width>
<input type=hidden name=screen_height>
[input fields for username and password]
<input type=submit value="submit" onClick='fill_in_screensize();'>
</FORM>