Submenu items on top of each other

Hello, I have been stuck on this for days now and not getting anywhere.

I am trying to get the submenu items in a nice vertical list
e.g

item1
item2
item3

currently the submenu items are on top of each other horizontally.

eg.

item1 2 3

here is the call for the menu:

===================================================================
<div id=”navmenu”>
<div class=”menucontainer”>

<?php wp_nav_menu( array( ‘buddy’ => ‘top-nav’ , ‘container_class’ => ‘navmenu’ ) ); ?>

</div>
</div>
====================================================================

here is my css at the moment.

====================================================================
.navmenu {
background-color: #fff;
height: 42px;
font-size: 16px;
}

.navmenu ul,
div.menu ul {
width:100%;
max-width:1000px;
list-style-type:none;
display:block;
margin:0 auto;
padding: 0;
}

.navmenu li,
div.menu li {
float: left;
text-align: center;
width: 20%;
position: relative;
}

.navmenu ul ul {
display: none;
position: absolute;
top: 38px;
left: 0;
float: left;
width: auto;
z-index: 99999;
}

.navmenu a {
color: #ed1d78;
display: block;
line-height: 41px;
padding: 0 10px;
text-decoration: none;
font-weight: bold;
}

.navmenu ul li:hover > ul {
display: block;
}

.navmenu li:hover > a,
.navmenu ul ul :hover > a {
background: #ed1d78;
color: #D1CFCF;
}

.navmenu ul ul a {
background: #fff;
line-height: 1em;
padding: 10px;
width: 200px;
height: auto;
border-style: solid;
border-width: 1px;
border-color: ed1d78;
}
====================================================================

Any help would be greatly appreciated.

Thank you