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

I succeeded on chrome with :

    setTimeout(
       function(){
          $("#input_password").focus();
          $("#input_username").focus();
          console.log($("#input_username").val());
          console.log($("#input_password").val());
       }
    ,500);