Mine

Section "InputDevice"

# Identifier and driver

    Identifier  "Mouse1"
    Driver      "mouse"
    Option "Protocol"    "IMPS/2"       # IntelliMouse PS/2
    Option "Device"      "/dev/mouse"

# When using XQUEUE, comment out the above two lines, and uncomment
# the following line.

#    Option "Protocol"  "Xqueue"

# Mouse-speed setting for PS/2 mouse.

#    Option "Resolution"        "256"

# Baudrate and SampleRate are only for some Logitech mice. In
# almost every case these lines should be omitted.

#    Option "BaudRate"  "9600"
#    Option "SampleRate"        "150"

# Mouse wheel mapping.  Default is to map vertical wheel to buttons 4 & 5,
# horizontal wheel to buttons 6 & 7.   Change if your mouse has more than
# 3 buttons and you need to map the wheel to different button ids to avoid
# conflicts.

    Option "ZAxisMapping"   "4 5"
    Option "Buttons"        "5"

# Emulate3Buttons is an option for 2-button mice
# Emulate3Timeout is the timeout in milliseconds (default is 50ms)

#    Option "Emulate3Buttons"
#    Option "Emulate3Timeout"    "50"

# ChordMiddle is an option for some 3-button Logitech mice

#    Option "ChordMiddle"

EndSection