Cool. I have a nit: 91 for Mac meta/command is the left-hand button in webkit only. It's 224 in Firefox, and the right-hand one in webkit is 93. Also, how to

Cool. I have a nit: 91 for Mac meta/command is the left-hand button in webkit only. It's 224 in Firefox, and the right-hand one in webkit is 93. Also, how to I bind to page up/down?