var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

function encode64(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);
   } 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 =
   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;
}

/*var base64		= {
 charmap		: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
 encode			: function(str) {
  var ret		= "";
  var c, i, acc		= 0;
  var div		= 1;
  for(i=0,c=0;i<str.length;i++,c++) {
   acc			= acc*256 + str.charCodeAt(i);
   div			= div*4;
   ret			= ret + base64.charmap.charAt(parseInt(acc/div));
   acc			= acc % div;
   if(div==64) ret	= ret + base64.charmap.charAt(parseInt(acc)), acc = 0, div = 1,c++;
   if(c>=75) c=-1, ret	= ret + "\n";
  } if(i%3) {
   ret			= ret + base64.charmap.charAt(parseInt(acc*((i%3==1)?16:4)));
   ret			= ret + ((i%3)==1?"==":"=");
  } return ret;
 },
 decode			: function(str) {
  var ret		= "";
  var i, acc		= 0;
  var div		= 1;
  for(i=0;i<str.length;i++) {
   if(str.charAt(i)=="=" || str.charAt(i)=='\n') break;
   acc			= acc*64 + base64.charmap.indexOf(str.charAt(i));
   div			= (div==1?64:div/4);
   if(div!=64) {
    ret			= ret + String.fromCharCode(parseInt(acc/div));
    acc			= acc % div;
   }
  } return ret;
 }
}*/