Examples:
Option "ZAxisMapping" "X" # maps scroll to X axis
Option "ZAxisMapping" "Y" # maps scroll to Y axis
Option "ZAxisMapping" "4 5" # maps -/+ Z axis motion to buttons 4/5
Examples:
Option "ZAxisMapping" "X" # maps scroll to X axis
Option "ZAxisMapping" "Y" # maps scroll to Y axis
Option "ZAxisMapping" "4 5" # maps -/+ Z axis motion to buttons 4/5