Help with css selector for jquery

Question

I have this wordpress blog that has many pages with subpages that dropdown on hover.... the thing is, I dont want the pages that you hover to link to anything unless they dont have any ul with many anchors inside so just the subpages will have a href different than "#" So basically Im hacking my way through this with some simple javascript.

   jQuery(document).ready(function(){
   jQuery("#menus li > a").attr("href","#");
 });

This is selecting every a.. and I dont want that... I just want the anchors that are main pages, not subpages... heres the html so maybe you can think of a better way to select this.

Ill explain first

the structure is an ul with many li that have an anchor inside if the li also has a ul inside then those are subpages that will appear on hover. hence the initial anchor should have href="#" if there is no ul inside the li then the li a should keep its href.

    <ul id="menus">
      <li>
        <a href="somelink">Main Page</a> //href should be changed to #
        <ul>
            <li>
              <a href="somelink2/">Subpage1</a>
            </li>
            <li>
              <a href="somelink3">Subpage2</a>
            </li>
        </ul>
      </li>
      <li>
        <a href="somelink">MainPage-with-no-subpages</a> //href should not be changed
      </li>
      <li>
        <a href="somelink4">MainPage</a> //href should be changed to #
        <ul>
          <li>
            <a href="somelink5">Subpage</a>
          </li>
          <li>
            <a href="somelink6">Subpage</a>
          </li>
        </ul>
      </li>
</ul>

Answer 1

try

jQuery(document).ready(function(){
   jQuery("#menus li > ul").siblings('a').attr("href","#");
});

Answer 2

This should do what you want:

jQuery(document).ready(function(){
   jQuery("#menus li:has(ul) > a").attr("href","#");
}