how to check parent's parent's id equals

Question

<ul id="productmenu">
    <li>
      <a ref="#"></a>
    </li>
</ul>

how to check if a link's parent's parent has got an id = "productmenu"? I tried with PrentNode, but it did not work.

Answer 1

var pid = $(this).closest('ul').attr('id');

Answer 2

if($(this).closest("ul").attr("id") == "productmenu"){
}