backlit keyboard on laptop Asus n56v with Xubuntu Linux

How to enable backlit keyboard on Asus n56v using Xubuntu Linux

first become root

su

then to switch ON

echo 3 > /sys/class/leds/asus::kbd_backlight/brightness on

to switch OFF

echo 0 > /sys/class/leds/asus::kbd_backlight/brightness off