How do you tell if a browser has auto filled a text-box? Especially with username & password boxes that autofill around page load.

My first question is when does this occur in the page load sequence? Is it before or after document.ready?

Secondly how can I use logic to find out if this occurred? Its not that i want to stop this from occurring, just hook into the event. Preferably something like this:

if (autoFilled == true) {

} else {

}

If possible I would love to see a jsfiddle showing your answer.

Possible duplicates

DOM event for browser password autofill?

Browser Autofill and Javascript triggered events

--Both these questions don't really explain what events are triggered, they just continuously recheck the text-box (not good for performance!).