RNG. WIP

rng.user.js

// ==UserScript==
// @name         RNG
// @namespace    http://vresod.github.io
// @version      0.5
// @description  keyboard shortcuts
// @include     *
// @author       Vresod
// @grant        none
// ==/UserScript==

(function() {
    'use strict';
    if (e.ctrlKey && e.altKey && e.which == 89) {
        var chance = prompt('0 to what number?', '5')
        var number = Math.floor(Math.random() * (chance - 1)); // returns a random integer from 0 to chance
        alert('Your number is ' +number+ '!');
    }
  }
)();