Array position on mouseclick

programming flash
1

I have two arrays thumbs and images, both the thumb and image are added to the same index in their arrays, so thumb[0] is the thumb of image[0]

but what I need to do is get the index position of the clicked item, how do i do this?

new_carousel_item.addEventListener(MouseEvent.CLICK, getValue);
new_carousel_item.buttonMode = true;
thumbs.push(new_carousel_item);

    public function getValue(evt:MouseEvent):void {
        
      //I cannot determing the index position
        
    }