function base64_encode( data ) 
{
    var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
    var o1, o2, o3, h1, h2, h3, h4, bits, i = ac = 0, enc="", tmp_arr = [];
    data = 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 base64_decode( data ) 
{
    var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
    var o1, o2, o3, h1, h2, h3, h4, bits, i = ac = 0, dec = "", tmp_arr = [];
 
    data += '';
 
    do 
	{  // unpack four hexets into three octets using index points in b64
        h1 = b64.indexOf(data.charAt(i++));
        h2 = b64.indexOf(data.charAt(i++));
        h3 = b64.indexOf(data.charAt(i++));
        h4 = b64.indexOf(data.charAt(i++));
 
        bits = h1<<18 | h2<<12 | h3<<6 | h4;
 
        o1 = bits>>16 & 0xff;
        o2 = bits>>8 & 0xff;
        o3 = bits & 0xff;
 
        if (h3 == 64) 
		{
            tmp_arr[ac++] = String.fromCharCode(o1);
        } 
		else 
		if (h4 == 64) 
		{
            tmp_arr[ac++] = String.fromCharCode(o1, o2);
        } 
		else 
		{
            tmp_arr[ac++] = String.fromCharCode(o1, o2, o3);
        }
    } 
	while (i < data.length);
 
    dec = tmp_arr.join('');
	
	// dec = utf8_decode(dec);
 
    return dec;
}

function utf8_decode ( str_data ) 
{
 
    var tmp_arr = [], i = ac = c1 = c2 = c3 = 0;
    str_data += '';
 
    while ( i < str_data.length ) 
	{
		c1 = str_data.charCodeAt(i);
        if (c1 < 128) 
		{
            tmp_arr[ac++] = String.fromCharCode(c1);
            i++;
        } 
		else 
		if ((c1 > 191) && (c1 < 224)) 
		{
            c2 = str_data.charCodeAt(i+1);
            tmp_arr[ac++] = String.fromCharCode(((c1 & 31) << 6) | (c2 & 63));
            i += 2;
        } 
		else 
		{
            c2 = str_data.charCodeAt(i+1);
            c3 = str_data.charCodeAt(i+2);
            tmp_arr[ac++] = String.fromCharCode(((c1 & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
            i += 3;
        }
    }
 
    return tmp_arr.join('');
}