function Animation(img, w, h, domElem) {
	
	var img = this.img = img; 
	var domElement = this.domElement = domElem;
	this.playing = true; 
	this.looping = true;
	this.width = w; 
	this.height = h;
	this.x = 0; 
	this.y = 0; 
	this.rotation = 0;
	this.offsetX = 0; 
	this.offsetY = 0; 
	this.spriteSheetWidth = this.img.width; 
	this.numFrames = Math.floor(this.spriteSheetWidth/this.width);
	this.currentFrame = 0; 
	
	if(!this.domElement)
	{
		this.domElement = document.createElement('div');
		this.domElement.className = "animation";
		this.domElement.style.background = 'url('+img.src+')';
		this.domElement.style.width = this.width+"px"; 
		this.domElement.style.height = this.height+"px";
	}

	this.update = function()
	{
		if(this.playing)
		{
			var nextFrame = this.currentFrame + 1;
			
			if(nextFrame >= this.numFrames)
			{
				if(this.looping)
				{
					this.gotoAndStop(0);
				}
				else
				{
					this.playing = false; 
					this.gotoAndStop(this.numFrames - 1); 
				}
			}
			else
			{
				this.gotoAndStop(nextFrame);
			}
		}
	};
	
	this.render = function()
	{
		var dom = this.domElement; 	
		var offset = this.currentFrame * this.width; 
	
		dom.style.background = 'url(' + img.src + ')'; 
		dom.style.width = this.width + "px"; 
		dom.style.height = this.height + "px";
		dom.style.backgroundPosition = offset + "px 0 ";
		
		var xp = Math.round(this.x + this.offsetX);
		var yp = Math.round(this.y + this.offsetY);
		
		styleStr = "translate(" + xp + "px, " + yp + "px)";
		dom.style.webkitTransform = styleStr;
		dom.style.MozTransform = styleStr;
		dom.style.OTransform = styleStr;
		dom.style.transform = styleStr;
		
		styleStr = "rotate(" + this.rotation + "deg)";
		dom.style.webkitTransform += styleStr;
		dom.style.MozTransform += styleStr;
		dom.style.OTransform += styleStr;
		dom.style.transform += styleStr;
	};

	this.play = function()
	{
		this.playing = true; 
	};
	
	this.gotoAndStop = function(framenum)
	{
		this.currentFrame = framenum;
	};
	
	this.stop = function()
	{
		this.playing = false; 
	};
}