Post a JavaScript

I'm currently working on a simple JavaScript effects library called Jasoop.

jasoop.js:

Code:

var Effect = (function() {
    var durations = {
        "very fast": 500,
        "fast": 750,
        "normal": 1000,
        "slow": 1500,
        "very slow": 2000
    },
    styles = [],
    counter = 0,
    fader = setTimeout(function() {
        return

...