Create a function to read a FileStream and return a string

public static string ReadFileStream(System.IO.FileStream fs)
{
	// declare a stringbuilder class to hold our data
	StringBuilder sbWork = new StringBuilder();

	// make sure our StringBuilder work variable is big enough
	sbWork.EnsureCapacity((int)fs.Length);
	// empty the work variable
	sbWork.Length = 0;

	int nByte; // variable to hold the current byte.
	bool bReturnNull = true; // holds flag to determine if the function should return NULL

	// read each byte in the file stream.
	while ((nByte = fs.ReadByte()) >= 0)
	{
		// set the flag so we know to NOT return NULL.
		bReturnNull = false;

		// convert the byte to a character.
		char cTemp = (char)nByte;
		// append the character to our work variable.
		sbWork.Append(cTemp);				
	}

			
	if (bReturnNull)
	{
		return null;
	}
	else
	{
		return sbWork.ToString();
	}
}