multilevel vertical unorder list menu

alt text http://www.pwiser.com/error.pnghi i want to make unorder list based menu unable to figure it out i attached the image for better understanding please help below is my css and xhtml

#verticalSubmenu ul
{
margin: 0;
padding: 0;
list-style-type: none;
font-family: Arial, Helvetica, sans-serif;
font-size: 11px;
text-transform:uppercase;
}

#verticalSubmenu li { margin: 0 0 3px 0; background:#dedede; border: 1px solid #f7f7f7; color:#666666;  height:auto;
 }
#verticalSubmenu li.parent { background:#6c6b6b; color:#fcfafa; height:auto;
}

#verticalSubmenu a
{
    display: block;
    padding: 4px 2px 2px 10px;
    width: 138px;

}

#verticalSubmenu li a:link, #navlist a:visited{
color: #666666;
text-decoration: none;
}

#verticalSubmenu li.parent a:link, #navlist a:visited
{
color: #fcfafa;
}
#verticalSubmenu ul ul {
    position:relative;
    height:0;
    top:10px;
    left:0; 
    }
#verticalSubmenu ul ul li{
    background:#f9f9f9;
    border:1px solid #f9f9f9;
    }
#verticalSubmenu ul ul a{
    padding: 4px 2px 2px 20px;
    height:auto;
    }

<div id="verticalSubmenu">
                <ul id="navlist">
                    <li class="parent"><a href="#">Item one</a></li>
                    <li><a href="#">Item two</a></li>
                    <li><a href="#">Item three</a></li>
                    <li><a href="#">Item four</a></li>
                    <li>
                        <a href="#">Item five</a>
                        <ul>
                            <li> <a href="#">Item six</a></li>
                            <li> <a href="#">Item six</a></li>
                            <li> <a href="#">Item six</a></li>
                            <li> <a href="#">Item six</a></li>
                        </ul>
                    </li>
                <li><a href="#">Item four</a></li>
                </ul>
            </div>