Touchpad shell script

#!/bin/sh

# toggle synaptic touchpad on/off

# get current state

SYNSTATE=$(synclient -l | grep TouchpadOff | awk '{ print $3 }')

lsusb | grep -i mouse > /dev/null
MPLUGGED=$?

on()
{
    synclient TouchpadOff=0
    synclient VertEdgeScroll=1
    synclient HorizEdgeScroll=1
    synclient MaxSpeed=4.5 #6
    synclient MinSpeed=1
    synclient VertTwoFingerScroll=1
    synclient HorizTwoFingerScroll=1
    synclient TapButton1=1
    synclient TapButton2=0 #3
    synclient TapButton3=2
    #synclient EmulateTwoFingerMinZ=90
    synclient VertScrollDelta=10
    synclient HorizScrollDelta=10
    #synclient MaxTapTime=0
    synclient CoastingSpeed=0.8
    synclient PalmDetect=1
    synclient PalmMinZ=10
    synclient PalmMinWidth=200
    #synclient CircularPad=1
    echo "Touchpad enabled!"
    #zenity --notification --text="Touchpad enabled!" --window-icon=info
    notify-send --expire-time=2500 -i info "Touchpad" "The touchpad has been enabled!"
}

off()
{
    synclient touchpadoff=1
    echo "Touchpad disabled!"
    #zenity --notification --text="Touchpad disabled!" --window-icon=info
    notify-send --expire-time=2500 -i error "Touchpad" "The touchpad has been disabled!"
}

toggle()
{
    if [ $MPLUGGED = 0 ]; then
        off
        echo "External USB Mouse present!"
        exit
    fi
    # change to other state
    if [ $SYNSTATE = 0 ]; then
        off
    elif [ $SYNSTATE = 1 ]; then
        on
    else
        echo "What the heck?!"
    fi
}

if [ "$#" = "0" ]; then
    toggle
elif [ "$1" = "on" ]; then
    on
elif [ "$1" = "off" ]; then
    off
else
    echo "Touchpad is: $SYNSTATE"
fi