link = "http://www.google.com";
doc.querySelectorAll('#courses_menu > ul > li > a'); // Apply on the link.

<iframe id="holder" style="display: none">

<script type="text/javascript">
$("#holder").load("http://www.google.com",function () {
  $link = $("#holder").contents().find("#courses_menu > ul > li > a");
});
</script>