Edit in JSFiddle

<div id="menucontainer">
    <ul id="hmenu">
        <li class="parent_menu"><a href="#">Home</a>

        </li>
        <li class="parent_menu"><a href="#">About</a>

            <ul>
                <li class="child_menu"><a href="#">Test 1</a>

                </li>
              <li class="child_menu"><a href="#">Test 2</a>
                </li>
            </ul>
        </li>
        <li class="parent_menu"><a href="#">Contact Us</a>

            <ul>
                <li class="child_menu"><a href="#">Test 1</a>
                </li>
                <li class="child_menu"><a href="#">Test 2</a>
                </li>
                <li class="child_menu"><a href="#">Test 3</a>
                </li>
            </ul>
        </li>
        <li class="parent_menu"><a href="#">Information</a>
            <ul>
                <li class="child_menu"><a href="#">Test 1</a>
               </li>
                <li class="child_menu"><a href="#">Test 2</a>
                </li>
                <li class="child_menu"><a href="#">Test 3</a>
                </li>
                <li class="child_menu"><a href="#">Test 4</a>
                </li>
            </ul>
        </li>
    </ul>
</div>