Javascript fade in fade out without Jquery and CSS3

Question

I am really squeezing my head to make the simple fade in and fade out of the background image work only with javascript without JQuery and CSS3. I know how easy is to call a

Answer 1

getElementById givies you one element (or null), getElementsByClassName gives an array.

function handleClick(evt){
    var element = document.getElementById(evt.target.id);
    fade(element);

}

You seem to aim for usage of ID's, so this should answer your needs. I updated the whole thing: IDs

However, you should realize that this method of fading is much more costly than using GPU accelerated transitions.

Update
JSfiddle webkit opacity fade