Disable internal keyboard of a laptop running on Ubuntu 14.04 LTS

Recently I need to use a very old laptop, which happens to have some of its internal keyboard damaged, i attached an external keyboard via usb but the internal keyboard keeps interfere with the terminal input and the GUI (possibly due to malfunction that causes some keys to be pressed permanently). Therefore, I decided to disable the internal keyboard of the laptop, and now everything works wonderfully. The way to do this is as following:

1. Open a terminal, and run the following command:

> xinput list

2. Take note of the id in the line that reads "AT Translated Set 2 Keyboard", in my laptop it is 14. Now run the following command to disable it:

> xinput float 14

By the way, to re-enable run "xinput reattach 14".