Why Does this Not Work in IE 9? (jquery)

JavaScript
1

The following codes moves the form below the comment that’s being replied to. But it doesn’t work in IE9 when I try it. In IE the form just stays hidden…

Anyone got any idea why?

// Threaded comments - will set proper parent_id and move the form
$(document).ready(function(){
  $('.reply').click(function() {
    $('.formThreaded input[name=parent_id]').val($(this).attr('rel'));
    $('.formThreaded').insertAfter( // Insert the comment form after...
    $(this)
    .parent() // The containing p tag
    );
    $('.formThreaded').show();
  });
});