None techie here, so be kind. I have been given a different mouse, which has right and left click plus a scroll facility. My mate dropped it in just now but had to rush so couldn't explain details and I want to use it tonight if possible. The old mouse ( single click ) is years old and came with the 2nd hand G4 and playing up, freezing, needing unplugging from USB on keyboard. What do the two side clicks do that's different please?