Change input value throwing an event with js

I've an input field that can be modify by users and js buttons. I need to throw an event when the user writes/deletes something in the textarea and when a button modifies the value of the input without using jQuery.

I tried to overwrite input's get and set methods but when I change input text with js before modify it by my hand and change it again with js the displayed text in the input box doesn't change.

It has to work on IE11 and Chrome (cannot use onpropertychange event).

I'm sorry for my bad english but i hope I was clear.