Parent / Child script

i have this script working fine, but just wanted to know if theres anyway i can change it so when u click the list drops down and when u click again it dissapears, its the dissapearing part i cant seem to do!
any help would be appreciated thanks!


<script type="text/javascript">
var currentOpen = null;
var pLinks = [
{loc:"onlineturncard2.htm#Goalkeeper"} ,
{loc:"onlineturncard2.htm#Defenders"} ,
{loc:"onlineturncard2.htm#Midfielders"} ,
{loc:"onlineturncard2.htm#Attackers"} ,
{loc:"onlineturncard2.htm#Substitutes"} ,
];

function handleParent(parentId)
{
(pLinks[parentId-1].loc, "mainFrame", pLinks[parentId-1].winOpt);
myParent = document.getElementById("menu" + parentId);
if(currentOpen != null) {
currentOpen.style.display = "none";
}
currentOpen = myParent;

if (myParent.style.display=="none") {
myParent.style.display="block";
} else {
currentOpen = null;
myParent.style.display="none";
}
}
</script>