var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

function encode64(input) {
   var output = "";
   if (input != "") {   
   	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);
   	} while (i < input.length);
   } 
   return output;
}

function decode64(input) {
   var output = "";
   if (input != "") {
	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, "");

   	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);
      		}
   	} while (i < input.length);
   }
   return output;
}
function encode64Han(str) {
  if (str !="") {return encode64(escape(str))}
  else {return ""}
}
function decode64Han(str) {
  if (str !="") {return unescape(decode64(str))}
  else {return ""}
}