Detecting Browser Autofill

Question

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

Answer 1

For google chrome autocomplete, this worked for me:

if ($("#textbox").is(":-webkit-autofill")) 
{    
    // the value in the input field of the form was filled in with google chrome autocomplete
}