fade-in menu

[wxdqz]

ok, i have this script for my site's dynamic nav-bar, but how do i make the document.menu.folders[curobj] object fade in?

menu.js
<!--
var i = 0
var ie5 = document.all ? 1 : 0
var ns4 = document.layers ? 1 : 0
var ns6 = document.getElementById && !document.all ? 1 : 0
document.menu = new Object()
document.menu.folders = new Array()

function expand(curobj) {
for (i in document.menu.folders) {
document.menu.folders.display = 'none'
i++
}

i = 0
document.menu.folders[curobj].style.display = ''

return 0
}

function contract(curobj) {
document.menu.folders[curobj].style.display = 'none'

return 0
}

function getFolders() {
if (ie5) {
for (i = 0; i < document.all.length; i++) {
if (document.all.className == 'FOLDER')
document.menu.folders[document.menu.folders.length] = document.all
}
} else if (ns6) {
var contained = document.getElementsByTagName('div')

for (i = 0; i < contained.length; i++) {
if (contained.getAttribute('class') == 'FOLDER')
document.menu.folders[document.menu.folders.length] = contained
}
}

return 0
}

function doExpand() {
return
}
//-->


any help will greatly be appreciated