/**
*
*  Base64 encode / decode
*  http://www.webtoolkit.info/
*
**/
var ua = navigator.userAgent.toLowerCase();
if (ua.indexOf(" chrome/") >= 0 || ua.indexOf(" firefox/") >= 0 || ua.indexOf(' gecko/') >= 0) {
	var StringMaker = function () {
		this.str = "";
		this.length = 0;
		this.append = function (s) {
			this.str += s;
			this.length += s.length;
		}
		this.prepend = function (s) {
			this.str = s + this.str;
			this.length += s.length;
		}
		this.toString = function () {
			return this.str;
		}
	}
} else {
	var StringMaker = function () {
		this.parts = [];
		this.length = 0;
		this.append = function (s) {
			this.parts.push(s);
			this.length += s.length;
		}
		this.prepend = function (s) {
			this.parts.unshift(s);
			this.length += s.length;
		}
		this.toString = function () {
			return this.parts.join('');
		}
	}
} 
 
var Base64 = {
 
	// private property
	keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
 
	// public method for encoding
	encode : function (input) {
		var output = new StringMaker();
		var chr1, chr2, chr3;
		var enc1, enc2, enc3, enc4;
		var i = 0;
	
		while (i < input.length) {
			chr1 = input.charCodeAt(i++);
			chr2 = input.charCodeAt(i++);
			chr3 = input.charCodeAt(i++);
	
			enc1 = chr1 >> 2;
			enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
			enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
			enc4 = chr3 & 63;
	
			if (isNaN(chr2)) {
				enc3 = enc4 = 64;
			} else if (isNaN(chr3)) {
				enc4 = 64;
			}
	
			output.append(this.keyStr.charAt(enc1) + this.keyStr.charAt(enc2) + this.keyStr.charAt(enc3) + this.keyStr.charAt(enc4));
		}
	
		return output.toString();
	},
 
	// public method for decoding
	decode : function (input) {
		var output = new StringMaker();
		var chr1, chr2, chr3;
		var enc1, enc2, enc3, enc4;
		var i = 0;
	
		// remove all characters that are not A-Z, a-z, 0-9, +, /, or =
		input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
	
		while (i < input.length) {
			enc1 = this.keyStr.indexOf(input.charAt(i++));
			enc2 = this.keyStr.indexOf(input.charAt(i++));
			enc3 = this.keyStr.indexOf(input.charAt(i++));
			enc4 = this.keyStr.indexOf(input.charAt(i++));
	
			chr1 = (enc1 << 2) | (enc2 >> 4);
			chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
			chr3 = ((enc3 & 3) << 6) | enc4;
	
			output.append(String.fromCharCode(chr1));
	
			if (enc3 != 64) {
				output.append(String.fromCharCode(chr2));
			}
			if (enc4 != 64) {
				output.append(String.fromCharCode(chr3));
			}
		}
	
		return output.toString();
	}
 
}