Jump to the top of page a Product Page

Is there any way to jump to the top of a product page? 

Since I can't add another purchase button to the additional info part of a product page, I am adding a button at the bottom of the page that would jump to the Add to Cart button at the top. But when I use the #item ID as an anchor link, it jumps to the additional info part of the page (not to the very top).