At the touch of a button, a frame opens, the page opens internal. There are several buttons in the frame, they do not work, i.e. nothing happens by clicking them at all. If you go to this page without a frame, then everything works fine and the buttons are clickable
button code in the frame
<input type="button" class="button" value="{$smarty.const.CART_PROCEED_TO_CHECKOUT}" onClick="{if $cart_amount<$smarty.const.CONF_MINIMAL_ORDER_AMOUNT}document.getElementById('id_too_small_order_amount').style.display='block';return false;{/if}window{if $this_is_a_popup_cart_window}.opener{/if}.location='index.php?quick_register=yes';{if $this_is_a_popup_cart_window}window.close();{/if}"> frame opening code
<a class="iframe" href="cart.php?addproduct={$product_info.productID}">{$smarty.const.ADD_TO_CART_STRING}</a> 