Test 'input' event

HTML

<input id="my-text-box"></input>

<div id="messages" style="white-space:pre;"></div>

JavaScript

var input = document.querySelector('#my-text-box');

var messages = document.querySelector('#messages');

input.addEventListener('change', () => input.hasChanged = true);
input.addEventListener('blur', () => 
{
		if (!input.hasChanged) { return; }
		input.hasChanged = false;
    // Do your stuff
});