function base64_encode(data) {
    var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
    var o1, o2, o3, h1, h2, h3, h4, bits, i = 0, ac = 0, enc="", tmp_arr = [];
 
    if (!data) {
        return data;
    }
 
    data = this.utf8_encode(data+'');
    
    do { // pack three octets into four hexets
        o1 = data.charCodeAt(i++);
        o2 = data.charCodeAt(i++);
        o3 = data.charCodeAt(i++);
 
        bits = o1<<16 | o2<<8 | o3;
 
        h1 = bits>>18 & 0x3f;
        h2 = bits>>12 & 0x3f;
        h3 = bits>>6 & 0x3f;
        h4 = bits & 0x3f;
 
        // use hexets to index into b64, and append result to encoded string
        tmp_arr[ac++] = b64.charAt(h1) + b64.charAt(h2) + b64.charAt(h3) + b64.charAt(h4);
    } while (i < data.length);
    
    enc = tmp_arr.join('');
    
    switch (data.length % 3) {
        case 1:
            enc = enc.slice(0, -2) + '==';
        break;
        case 2:
            enc = enc.slice(0, -1) + '=';
        break;
    }
 
    return enc;
}

function utf8_encode ( argString ) {
    var string = (argString+''); // .replace(/\r\n/g, "\n").replace(/\r/g, "\n");
 
    var utftext = "";
    var start, end;
    var stringl = 0;
 
    start = end = 0;
    stringl = string.length;
    for (var n = 0; n < stringl; n++) {
        var c1 = string.charCodeAt(n);
        var enc = null;
 
        if (c1 < 128) {
            end++;
        } else if (c1 > 127 && c1 < 2048) {
            enc = String.fromCharCode((c1 >> 6) | 192) + String.fromCharCode((c1 & 63) | 128);
        } else {
            enc = String.fromCharCode((c1 >> 12) | 224) + String.fromCharCode(((c1 >> 6) & 63) | 128) + String.fromCharCode((c1 & 63) | 128);
        }
        if (enc !== null) {
            if (end > start) {
                utftext += string.substring(start, end);
            }
            utftext += enc;
            start = end = n+1;
        }
    }
 
    if (end > start) {
        utftext += string.substring(start, string.length);
    }
 
    return utftext;
}
