I have an old iMac G4 that I brought used 4 months ago. It came with a Pro Keyboard, the one with the USB ports on the back, but it didn't come with a mouse. I have an Hockey Puck Mouse which I decided to use, but it has two problems: one-button and no scrolling. I discovered that by holding ctrl and pressing the button it actually right-click. But scrolling is a problem: I don't know how to use scrolling with that mouse! Does anyone know how I can use the keyboard for scrolling?