// This code was written by Tyler Akins and has been placed in the
// public domain.  It would be nice if you left this header intact.
// Base64 code from Tyler Akins -- http://rumkin.com

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 keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

function encode64(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(keyStr.charAt(enc1) + keyStr.charAt(enc2) + keyStr.charAt(enc3) + keyStr.charAt(enc4));
	}

	return output.toString();
}

function decode64(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 = keyStr.indexOf(input.charAt(i++));
		enc2 = keyStr.indexOf(input.charAt(i++));
		enc3 = keyStr.indexOf(input.charAt(i++));
		enc4 = 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();
}