please help with javascript function

Im using this script for greasemonkey but its not working could somebody please help me

Code (text):

// ==UserScript==

// @name        tweepi

// @namespace   tweepi

// @description tweepi

// @include     http://tweepi.com/tools/follow_by_followers#0

// @version     1

// @grant       none

// ==/UserScript==

var input=document.createElement("input");

input.type="button";

input.value="GreaseMonkey Button";

input.onclick = showAlert;

document.body.appendChild(input);

function showAlert()

{…

please help with javascript function

See original post by Arclite