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);
		}
}