Easy way to get base64 encode and decode of a string

denCode.js

if (Object['defineProperty'] && !String.prototype.hasOwnProperty('deCode')) Object.defineProperty(String.prototype, 'deCode', { value: function() { return decodeURIComponent(unescape(window.atob(this))); } });
if (Object['defineProperty'] && !String.prototype.hasOwnProperty('enCode')) Object.defineProperty(String.prototype, 'enCode', { value: function() { return window.btoa(escape(encodeURIComponent(this))); } });

var a = 'GitHub'.enCode(); // a = "R2l0SHVi"
var b = a.deCode(); // b = "GitHub"