var ourInterval;
var scrollSpeed = 25;
var scrollHeight = 5;

function scrollStart(direction, divID, elementID){
ourInterval = setInterval("scroll"+direction+"('"+divID+"')", scrollSpeed);
}
function scrollEnd(which){
clearInterval(ourInterval);
}
function scrollUp(which){
document.getElementById(which).scrollTop = document.getElementById(which).scrollTop - scrollHeight;
}
function scrollDown(which){
document.getElementById(which).scrollTop = document.getElementById(which).scrollTop + scrollHeight;
}