protected static int SetUInt64(byte[] Data, UInt64 Value, int Pos)
{
byte[] ValueData = new byte[sizeof(UInt64)];
ValueData = BitConverter.GetBytes(Value);
// flipping the Array ....Big Endian ..
ValueData = FlipArray(ValueData);
Array.Copy(ValueData, 0, Data, Pos, ValueData.Length);
return Pos + sizeof(UInt64);
}