Target area effect while still dragging

Flash MX 2004. My drag and drop is working fine, but now I want the target area to highlight or something while the mouse is over it but not released yet, like its confirming the target area I want to drop in. The target area is several irregular polygon shapes. I would prefer if the target area would show an outline around the area.

My button try didn’t work because I’m already pressed down on another button (the one I’m dragging).

Thanks,
Jim