IE .last() issue

IE .last() issue

At some point of my code I need to extract the id attribute of an input element of the web form, wich is structured in a table format.

So I decided to use the next code:
  1. id_input = $('tr').children($('input[type="hidden"]').last().attr('id'));

It works fine in Chrome, FF and Safari, but brokes under IE 7+

The var 'id_input' returns in blank.

¿There's any solution without using CSS?