How to change visibility of a panel from within a class

I am using Flex with papervision 3d and tweener and i have a 3D spinning earth and on its surface i have some hotspots which are planes.
On the mxml file i have a Panel which has the visibility set to false, i have added an eventlistener for the hotspot so that when i click it the Panel should become visible, but i have no idea how to code that function so that it works, i don’t know how to adress the Panel’s visibility property, i don’t know how to change it from there.

I would really need some help with this.
Thank you, much appreciating.