When you want to have the page jump to the top of an iframe upon clicking “Next” or “Submit”, etc, you can easily use this code:

<iframe width="620" scrolling="no" height="2500" frameborder="0" style="background-color: transparent; overflow: hidden;" allowtransparency="true" src="http://www.website.com" onload="window.parent.parent.scrollTo(0,0);"></iframe>