How do I normalize CSS3 Transition functions across browsers?

There's a technique used in Modernizr, improved:

function transitionEndEventName () {
    var i,
        undefined,
        el = document.createElement('div'),
        transitions = {
            'transition':'transitionend',
            'OTransition':'otransitionend',  // oTransitionEnd in very old Opera
            'MozTransition':'transitionend',
            'WebkitTransition':'webkitTransitionEnd'
        };

    for (i in transitions) {
        if (transitions.hasOwnProperty(i) && el.style[i] !== undefined) {
            return transitions[i];
        }
    }

    //TODO: throw 'TransitionEnd event is not supported in this browser'; 
}

Then you can just call this function whenever you need the transition end event:

var transitionEnd = transitionEndEventName();
element.addEventListener(transitionEnd, theFunctionToInvoke, false);

As per Matijs comment, the easiest way to detect transition events is with a library, jquery in this case:

$("div").bind("webkitTransitionEnd.done oTransitionEnd.done otransitionend.done transitionend.done msTransitionEnd.done", function(){
  // Unlisten called events by namespace,
  // to prevent multiple event calls. (See comment)
  // By the way, .done can be anything you like ;)
  $(this).off('.done')
});

In library-less javascript it gets a bit verbose:

element.addEventListener('webkitTransitionEnd', callfunction, false);
element.addEventListener('oTransitionEnd', callfunction, false);
element.addEventListener('transitionend', callfunction, false);
element.addEventListener('msTransitionEnd', callfunction, false);

function callfunction() {
   //do whatever
}

Update

The following is a cleaner way of doing it, and doesn't require modernizr

$(".myClass").one('transitionend webkitTransitionEnd oTransitionEnd otransitionend MSTransitionEnd', 
function() {
 //do something
});

---

Alternatively

var transEndEventNames = {
        'WebkitTransition': 'webkitTransitionEnd',
        'MozTransition': 'transitionend',
        'OTransition': 'oTransitionEnd otransitionend',
        'msTransition': 'MSTransitionEnd',
        'transition': 'transitionend'
    }, transitionEnd = transEndEventNames[Modernizr.prefixed('transition')];

This is based on the code suggested by Modernizr, but with the extra event for newer versions of Opera.

http://modernizr.com/docs/#prefixed