Show Hide DIV Webpage

<script language="JavaScript">

function hidediv() {
if (document.getElementById) { // DOM3 = IE5, NS6
document.getElementById('mysubmenuarea').style.visibility = 'hidden';
document.getElementById('mysubmenuarea').style.display = "none";
}
else {
if (document.layers) { // Netscape 4
document.mysubmenuarea.visibility = 'hidden';
document.getElementById('mysubmenuarea').style.display = "none";
}
else { // IE 4
document.all.mysubmenuarea.style.visibility = 'hidden';
document.getElementById('mysubmenuarea').style.display = "none";
}
}
}

function showdiv() {
if (document.getElementById) { // DOM3 = IE5, NS6
document.getElementById('mysubmenuarea').style.visibility = 'visible';
document.getElementById('mysubmenuarea').style.display = 'block';
}else {
if (document.layers) { // Netscape 4
document.mysubmenuarea.visibility = 'visible';
}else { // IE 4
document.all.mysubmenuarea.style.visibility = 'visible';
}
}
}
</script>


----| CALL IN EVENT |---------
onmouseover="javascript: return showdiv();" onmouseout="javascript: return showdiv();"