How can UP/DOWN scroll be distinguished??

he easiest way for me to tell was...

var tempScrollTop, currentScrollTop = 0;

$("#div").scroll(function(){

currentScrollTop = $("#div").scrollTop();

if (tempScrollTop < currentScrollTop )
//scrolling down
else if (tempScrollTop > currentScrollTop )
//scrolling up

tempScrollTop = currentScrollTop;
}

This works with mousewheel, up/down arrows, and slidebar