Integrated Back Button

I’ve created a very simple website that uses frames as pages - nothing more. It has 6 frames and six buttons in every one of them
for navigation.

Now I want to integrate a BACK button - A simple button that will stand on every frame, and that will react [COLOR=blue]on (release)[/COLOR] [COLOR=black]in the way that will take us back to the last frame visited.[/COLOR]

Example: I start on frame 1. I press button 5 to go to the *frame 5. *Then, when I hit the back button (the integrated one - not browsers’) I want to get back to the frame 1.

Many thanks in advance!