create JS asset "base64" with code (to incode data into base64 format) 
 codevar Base64 = {
 
  // private property 
  _keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
 
  // public method for encoding 
  encode : function (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; 
  },
 
  // public method for decoding 
  decode : function (input) { 
   var output = "" 
   var chr1, chr2, chr3; 
   var enc1, enc2, enc3, enc4; 
   var i = 0;
 
   input = input.replace(/[A-Za-z0-9var Base64 = {
 
  // private property 
  _keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
 
  // public method for encoding 
  encode : function (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; 
  },
 
  // public method for decoding 
  decode : function (input) { 
   var output = ""; 
   var chr1, chr2, chr3; 
   var enc1, enc2, enc3, enc4; 
   var i = 0;
 
   input = input.replace(/[A-Za-z0-9\+\/\=]/g, "");
 
   while (i < input.length) {
 
    enc1 = this.keyStr.indexOf(input.charAt(i++)); 
    enc2 = this.keyStr.indexOf(input.charAt(i++)); 
    enc3 = this.keyStr.indexOf(input.charAt(i++)); 
    enc4 = this.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); 
    }
 
   }
 
   output = Base64._utf8_decode(output);
 
   return output;
 
  },
 
  // private method for UTF-8 encoding 
  _utf8_encode : function (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; 
  },
 
  // private method for UTF-8 decoding 
  _utf8_decode : function (utftext) { 
   var string = ""; 
   var i = 0; 
   var c = c1 = c2 = 0;
 
   while ( i < utftext.length ) {
 
    c = utftext.charCodeAt(i);
 
    if (c < 128) { 
     string += String.fromCharCode(c); 
     i++; 
    } 
    else if((c  191) && (c < 224)) { 
     c2 = utftext.charCodeAt(i+1); 
     string += String.fromCharCode(((c & 31) << 6) | (c2 & 63)); 
     i += 2; 
    } 
    else { 
     c2 = utftext.charCodeAt(i+1); 
     c3 = utftext.charCodeAt(i+2); 
     string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63)); 
     i += 3; 
    }
 
   }
 
   return string; 
  }
 
 }#47;\=]/g, "");
 
   while (i < input.length) {
 
    enc1 = this.keyStr.indexOf(input.charAt(i++)); 
    enc2 = this.keyStr.indexOf(input.charAt(i++)); 
    enc3 = this.keyStr.indexOf(input.charAt(i++)); 
    enc4 = this.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); 
    }
 
   }
 
   output = Base64._utf8_decode(output);
 
   return output;
 
  },
 
  // private method for UTF-8 encoding 
  _utf8_encode : function (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; 
  },
 
  // private method for UTF-8 decoding 
  _utf8_decode : function (utftext) { 
   var string = "" 
   var i = 0; 
   var c = c1 = c2 = 0;
 
   while ( i < utftext.length ) {
 
    c = utftext.charCodeAt(i);
 
    if (c < 128) { 
     string += String.fromCharCode(c); 
     i++; 
    } 
    else if((c > 191) && (c < 224)) { 
     c2 = utftext.charCodeAt(i+1); 
     string += String.fromCharCode(((c & 31) << 6) | (c2 & 63)); 
     i += 2; 
    } 
    else { 
     c2 = utftext.charCodeAt(i+1); 
     c3 = utftext.charCodeAt(i+2); 
     string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63)); 
     i += 3; 
    }
 
   }
 
   return string; 
  }
 
 }/code