The only hint I can give is to look through the MooTools API
documentation. But for your convenience, you can compare your original
script to the this (untested) version:
window.addEvent('domready', startnavigation);
function startnavigation(){
window.addEvent('scroll', function(){
var scrolltop = window.getScroll().y,
navigation = document.id('navigation');
if (scrolltop >= 320){
if (Browser.ie6) navigation.setStyle('top', (scrolltop
- 330));
else navigation.setStyles({position: 'fixed', top:
-60});
} else {
if (Browser.ie6) navigation.setStyle('position',
'absolute');
else navigation.setStyles({position: 'relative', top:
0});
}
});
}