var keyStr = "ABCDEFGHIJKLMNOP" +

       "QRSTUVWXYZabcdef" +

       "ghijklmnopqrstuv" +

       "wxyz0123456789+/" +

       "=";

var Base64 = {

	encode: function (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;

		}

	, decode : function (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);

		}

}