I am new to Javascript and trying to make a script in tampermonkey to automate button click.The thing that i want with this script is that it should click the button after page load.
Plus The Button Class,Id and button position is changing after every page refresh and button text is "Start".
**Something like this:**

```html
<a class="btn btn-small animated rubberBand valign-wrapper green" id="zOINDFblRN"><i class="material-icons left">launch</i> Start</a>
```

**Following code i have tried but it seems to not working :**

```js
// ==UserScript==
// @name         Auto
// @namespace    Munem2x
// @version      2
// @description  try to take over the world!
// @author       You
// @match        https://
// @grant        none
// ==/UserScript==
(function() {
document.getElementsByClassName("btn btn-small animated rubberBand valign-wrapper green")[0].click();

})();
```

I ll be thankful for your help.