How to Make a Page Menu Dropdown with Hierarchy?

Hi,

I’m trying to make a fancy dropdown menu for my pages. Some of my pages have subpages (children), some don’t. I’ve been playing with the wp_list_pages function but I cannot get the children to fit in. My static code looks like this and the question is how do I make it dynamic. Any ideas please?

<ul id="menu">
<li><a href="#">Page Element 1</a>
                    <ul class="dropdown">
		<li><a href="#">Child 1</a></li>
                <li><a href="#">Child 2</a></li>
                <li><a href="#">Child 3</a></li>
		    </ul>
            </li><!-- End Page Element -->
    </ul><!-- End Menu -->