function roll(elId) {
		if(rolling) {
			sliderEl = document.getElementById(elId);
			conveyorEl = document.getElementById('conveyor');
			if(sliderEl && conveyorEl) {
				sliderW = sliderEl.offsetWidth;
				conveyorW = conveyorEl.offsetWidth;
				scrollRange = sliderW - conveyorW;
				if(rollDirection) {
					newOffset = rollOffset - rollStep;
				} else {
					newOffset = rollOffset + rollStep;
				}	
				if(newOffset > 0) {
					StopRoll();
					newOffset = -5;
				}
				if(newOffset < (scrollRange * -1)) {
					StopRoll();
					newOffset = (scrollRange * -1) + 5;
				}
				
				rollOffset = newOffset;
				sliderEl.style.left = rollOffset+"px";
			}
			
		}
		setTimeout("roll('"+elId+"')",timeStep)
	}
function initRoller(elId) {
		roll(elId);
	}
function StartRoll(dir) {
		rollDirection = dir;
		rolling = true;
		//alert('Start!');
	}
function StopRoll() {
		rolling = false;
		//alert('Stop!');
	}