[jQuery] selecting elements in a nested table

Could someone help me out with the following problem. I've been
thinking about this for quite a while, but I just cannot think of a
solution to the problem at all.

Quite simply, I would like to leave the UL containing the LI with
class="active" open when the page is loaded,
all other elements should just display the heading, but not the
individual list items:

<ul class="mylist">

    <li>heading 1
        <ul>
            <li class="active">item</li>
            <li>item</li>
       </ul>
    </li>

    <li>heading 2
        <ul>
            <li>item</li>
        </ul>
    </li>

    <li>heading 3
        <ul>
            <li>item</li>
        </ul>
    </li>

</ul>

Thanks for your help!