How the frames work, and what is the consequence of having 3 frames on a page, and 2 menus in 2 frames out of those 3.

www.sector1online.de/mrs

The idea is.. is there anyway that i can do when you click for example on: home, spendenkonto etc. in the top menu, and then click on the left menu: der Vorstand, die Stifterung, etc. you can see that both menus have the buttons active, on red.

So how can i make it when you click on the left menu, the top menu should go to black. Or otherwise, when i click on the top menu the left menu should go to black.

Thank you so much,
Michael.