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('');
}