Paul Irish's requestAnimationFrame shim in coffeescript.

requestAnimationFrame

    lastTime = 0
    vendors = ['ms', 'moz', 'webkit', 'o']

    for x in vendors and not window.requestAnimationFrame
        window.requestAnimationFrame = window[vendors[x]+'RequestAnimationFrame']
        window.cancelAnimationFrame = window[vendors[x]+'CancelAnimationFrame'] or
        window[vendors[x]+'CancelRequestAnimationFrame']
        
    if not window.requestAnimationFrame
        window.requestAnimationFrame =  (callback, element) ->
            currTime = new Date().getTime()
            timeToCall = Math.max( 0, 16 - ( currTime - lastTime ) )

            id = window.setTimeout ->
                callback(currTime + timeToCall)
            , timeToCall

            lastTime = currTime + timeToCall

            return id