C++ CRC Calculation to C#

Can anyone help me with c++ code. I don't know much about CRC and the C++ sample is not making it easy for me.

I would like to send message from my application to a device using my serial port. The last two bytes of the message should have CRC (LSB) and CRC(MSB).

Sample CRC Calculation
//---------------------------------------------------------------------------
void UpdateCRC(unsigned short int *CRC, unsigned char x)
{
  // This function uses the initial CRC value passed in the first
  // argument, then modifies it using the single character passed
  // as the second argument, according to a CRC-16 polynomial
  // calculation used for HAI communication protocol.

  // Arguments:
  //   CRC -- pointer to starting CRC value
  //   x   -- new character to be processed

  // Returns:
  // The function does not return any values, but updates the variable
  // pointed to by CRC

  static int const Poly = 0xA001;    // CRC-16 polynomial
  int i;
  bool flag;

  *CRC ^= x;
  for (i=0; i<8; i++)
  {
    flag = ((*CRC & 1) == 1);
    *CRC = (unsigned short int)(*CRC >> 1);
    if (flag)
      *CRC ^= Poly;
  }
  return;
}