var keyStr = "ABCDEFGHIJKLMNOP" +
               "QRSTUVWXYZabcdef" +
               "ghijklmnopqrstuv" +
               "wxyz0123456789+/" +
               "=" +
			   " ";

function encode64(input) 
{
	input = escape(input);
	var output = "";
	var chr1, chr2, chr3 = "";
	var enc1, enc2, enc3, enc4 = "";
	var i = 0;

	do {
	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 = output +
	   keyStr.charAt(enc1) +
	   keyStr.charAt(enc2) +
	   keyStr.charAt(enc3) +
	   keyStr.charAt(enc4);
	chr1 = chr2 = chr3 = "";
	enc1 = enc2 = enc3 = enc4 = "";
	} while (i < input.length);

	return output;
}

function decode64(input) 
{
	var output = "";
	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 =
	var base64test = /[^A-Za-z0-9\+\/\=]/g;
	if (base64test.exec(input)) {
	alert("There were invalid base64 characters in the input text.\n" +
		  "Valid base64 characters are A-Z, a-z, 0-9, '+', '/',and '='\n" +
		  "Expect errors in decoding.");
	}
	input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");

	do {
	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 = output + String.fromCharCode(chr1);

	if (enc3 != 64) {
	   output = output + String.fromCharCode(chr2);
	}
	if (enc4 != 64) {
	   output = output + String.fromCharCode(chr3);
	}

	chr1 = chr2 = chr3 = "";
	enc1 = enc2 = enc3 = enc4 = "";

	} while (i < input.length);

	return unescape(output);
}