Click to Activate and Deactivate

Hi,
The situation that I have, its a multi object model with a details panel (3D Cube with Text as child) above it. I would like to have a details panel appear whenever its object is clicked on. If another object is selected the current active details panel will disappear and the new objects detail panel will appear in its place.
Any suggestion about the best way to approach this or code required that I could reference?
Thanks!!