Add to cart button not functioning

[Jeff Simons Decena]

hello everyone, maybe this is an easy for other but I have been looking around to get answer.

In my site:
http://www.fashionwerkz.com/product.php?id_product=1

The add to cart button is not functioning..but with other pages, my cart is ok. I am thinking on the product.tpl could be the problem. Maybe I missed some loops but double checked it and could not find what's wrong. Maybe someone knows?

btw, one of the code inside my buy_block form...

<form ...... >
......

quantity == 0} style="display:none;"{/if} id="add_to_cart" class="buttons_bottom_block"><input type="submit" name="Submit" value="{l s='Add to cart'}" class="exclusive" /></p>
.....
</form>