With the answer of my previous question, Textarea highlight on focus, I discovered an alternative to onfocus and onblur. These are onfocusin and onfocusout.
My question is, is there any differences between the two with how they behave?
This fiddle demonstrates that both appear the same: http://jsfiddle.net/spedwards/pQLAM/
focus and blur events do not bubble, so event delegation is impossible with those events.
focusin and focusout bubbles to the parent elements, and can be delegated.
Otherwise they are the same, but focusin and focusout is not part of any standard, but are in fact proprietary IE events, later adopted by some other browsers, but they are not supported cross browser.
Example
<div id=test>
<input type=text />
</div>
with js
var div = document.getElementById('test');
div.addEventListener('focus', handler, false); // does not work, focus does not bubble
div.addEventListener('focusin', handler, false); // works when input is focused, as the event bubbles
