if(document.addEventListener){
	document.addEventListener('DOMMouseScroll',scrollWheel,false);
	window.addEventListener('mousewheel',scrollWheel,false);
}else if(document.attachEvent){
	document.attachEvent('onmousewheel',scrollWheel,false);
}

var carPos = [];
var offset = -(cars[0].getWidth()/2);
for(var car in cars){
	car = cars[car];
	carPos.push(offset+car.x+(car.getWidth()/2));
}

var scrollPos = 0;
var autoScrollTo = false;
var targetX = 500;
function scrollWheel(e){
	var delta = 0;
	if(e.wheelDelta){
		delta = e.wheelDelta/120;
	}else if(e.detail){
		delta = -e.detail/3;
	}
	window.scrollBy(-delta*100,0);
	
	/*scrollPos = (document.all ? document.documentElement.scrollLeft : window.pageXOffset);
	var posDis = 0;
	var smallestDis = 1000;
	var closestPos;
	if(delta<0){
		for(var pos in carPos){
			pos = carPos[pos];
			if(pos<scrollPos){
				var posDis = Math.abs(scrollPos-pos);
				if(posDis>0 && posDis<smallestDis){
					smallestDis = posDis;
					closestPos = pos;
				}
			}
		}
	}
	targetX = closestPos;
	autoScrollTo = true;*/
}
/*function autoScroll(){
	scrollPos = (document.all ? document.documentElement.scrollLeft : window.pageXOffset);
	if(autoScrollTo){
		var dis = targetX-scrollPos;
		if(Math.abs(dis)>10){
			window.scrollBy(dis/10,0);
		}else{
			window.scroll(targetX,0);
			autoScrollTo = false;
		}
	}
}
addRenderFunction('autoScroll');
//var pos = (-cars[0].getWidth()/2)+(windowWidth/2)
//window.scroll(-(cars[0].getWidth()/2)+cars[2].x+(cars[2].getWidth()/2),0);*/