Dropdown menu - cross-browser compat...

I've made an attempt at creating a drop-down type menu, something like sgi.com, but I get some weird results:

1) It doesn't work in Netscape 4.5
2) in IE 4, when I mouse-over and -out of the submenus, the menus blink off for a split second...

Can anyone help me out? My attempt is at:
http://www.west.net/~grunion/test/menu.html

Thanks a lot!

I don't see any errors in my version of IE (5.0) but you spelled 'document' wrong here:

if ( document.layers ) { docuement.layers[id].visibility = "hidden" }

This would probably explain the problems in NS.

-- Martin