function hexEncode(data) {
    var b16_digits = '0123456789abcdef'; var b16_map = new Array(); for (var i = 0; i < 256; i++) { b16_map[i] = b16_digits.charAt(i >> 4) + b16_digits.charAt(i & 15); }
    var result = new Array(); for (var i = 0; i < data.length; i++) { result[i] = b16_map[data.charCodeAt(i)] + " "; }
    return result.join('');
}
function hexDecode(data) {
    var b16_digits = '0123456789abcdef'; var b16_map = new Array(); for (var i = 0; i < 256; i++) { b16_map[b16_digits.charAt(i >> 4) + b16_digits.charAt(i & 15)] = String.fromCharCode(i); }
    if (!data.match(/^[a-f0-9]*$/i)) return false; if (data.length % 2) data = '0' + data; var result = new Array(); var j = 0; for (var i = 0; i < data.length; i += 2) { result[j++] = b16_map[data.substr(i, 2)]; }
    return result.join('');
}