/** Base64 encode / decode   http://www.webtoolkit.info   **/
// private property
var _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
// public method for encoding
function _Base64_encode(input) {
var output = "";
var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
var i = 0;
input = _Base64_utf8_encode(input);
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 = output +
	this._keyStr.charAt(enc1) + this._keyStr.charAt(enc2) +
	this._keyStr.charAt(enc3) + this._keyStr.charAt(enc4);
}
return output;
}

// private method for UTF-8 encoding
function _Base64_utf8_encode(string) {
string = string.replace(/\r\n/g,"\n");
var utftext = "";

for (var n = 0; n < string.length; n++) {

	var c = string.charCodeAt(n);

	if (c < 128) {
		utftext += String.fromCharCode(c);
	}
	else if((c > 127) && (c < 2048)) {
		utftext += String.fromCharCode((c >> 6) | 192);
		utftext += String.fromCharCode((c & 63) | 128);
	}
	else {
		utftext += String.fromCharCode((c >> 12) | 224);
		utftext += String.fromCharCode(((c >> 6) & 63) | 128);
		utftext += String.fromCharCode((c & 63) | 128);
	}
}
return utftext;
}