I'm currently using CSS to style my buttons (still in HTML4) and I'd like to use one of these buttons for my web form. The code to get the web form to popup is
<a class='fb_iframe' href="http://coconut.coffeecup.com/forms/PROpoints/">Click here</a>

The code for my button is
<form>
<input class="MyButton" type="button" value="Submit PRO points online" onclick="window.location.href='http://coconut.coffeecup.com/forms/PROpoints/' " />
</form>
but this doesn't give me the popup (presumably because I'm not the class='fb_iframe')

Any idea how I can add this class to my button?