Changing Gallery Thumbnail hover

programming flash
1

I am trying to change the hover state on the XML Gallery thumbnail. I have created a mc in my library which is a colored border and given it the linkage name “border”.

I would like this mc to appear over the thumbnails in my scroller when the thumbnail is selected. I have adjused the AS as follows but my AS skills are basic, can anyone help please?

function thumbnails_fn(k) {
	thumbnail_mc.createEmptyMovieClip("t"+k, thumbnail_mc.getNextHighestDepth());
	tlistener = new Object();
	tlistener.onLoadInit = function(target_mc) {
		target_mc._x = hit_left._x+(target_mc._width+20)*k;
		target_mc.pictureValue = k;
		target_mc.onRelease = function() {
			p = this.pictureValue-1;
			nextImage();
		};
		target_mc.onRollOver = function() {
			border._alpha = 50;
			thumbNailScroller();
		};
		target_mc.onRollOut = function() {
			border._alpha = 100;
		};
	};