XML-Picture gallery problem?

Hello there…
I am trying to create a picture gallery…
I can arrange the thumbs in the screen and when I click to one of them, it shows the bigger picture.
But the problem is, I want the thumb to do something when the mouse is over it.
Let me show the code:

package {
	import com.greensock.easing.Expo;
	import com.greensock.easing.Cubic;
	import com.greensock.easing.EaseLookup;
	import com.greensock.TweenMax;
	import flash.events.MouseEvent;
	import flash.display.Sprite;

	/**
	 * @author emrea
	 */
	public class Thumbs extends Sprite 
	{
		private var xml : XML;
		private var thumb : Thumb;

		private var container : Sprite;
		private var app : App;
		
		private var currentImg  : Resim;
		private var oldImg : Resim;

		public function Thumbs(xml : XML, app : App)
		{
			this.app = app;
			this.xml = xml;
			container = new Sprite();
			addChild(container);
			container.y = 680;
			Init();
		}

		private function Init() : void 
		{
			var thumbY : int = -1;
			for (var i : int = 0;i < xml.item.length();i++) 
			{
				thumb = new Thumb(xml.item*.thumb);
				thumb.resimData = xml.item*.anaimaj;
				container.addChild(thumb);	
				thumb.addEventListener(MouseEvent.CLICK, onMsClick);
				thumb.addEventListener(MouseEvent.MOUSE_OVER, onMsOver);
				thumb.addEventListener(MouseEvent.MOUSE_OUT, onMsOut);
				thumb.x = (i % 2) * (200 + 5);
				if(i != 0) thumbY = (i % 2 == 0 ? thumbY - 105 : thumbY);
				thumb.y = thumbY;
				thumb.mouseChildren = false;
			}
		}
		private function onMsClick(event : MouseEvent) : void 
		{
			if(oldImg)
			{
				trace("ak")
				TweenMax.to(oldImg, 0.5, {alpha : 0 , ease : Cubic.easeOut, onComplete:Kill,onCompleteParams:[oldImg]});
			}
			
			currentImg = new Resim((Thumb(event.target)).resimData);
			this.addChild(currentImg);
			TweenMax.from(currentImg, 2, {alpha: 0 , ease : Cubic.easeIn});
			
			oldImg = currentImg;
		}
		
		private function Kill(resim : Resim) : void
		{
			removeChild(resim);
		}

		private function onMsOut(event : MouseEvent) : void 
		{
			TweenMax.to(this, 0.5, {alpha : 1,ease : Expo.easeOut});
		}

		private function onMsOver(event : MouseEvent) : void 
		{
			TweenMax.to(this,0.5,{alpha : 0.5,ease : Expo.easeOut});
		}

	}
}

When I use that tweenmax.to(this…) part, all the thumbs act like one.
I tried to change this to thumbs but i didn’t work.
What do you suggest me to convert all the thumbs to an individual image?