C# WinForm Write Text Log

public void LogMessage (string msg)
			{
			string sFilePath = Environment.CurrentDirectory + "Log_" + System.AppDomain.CurrentDomain.FriendlyName + ".txt";

			System.IO.StreamWriter sw = System.IO.File.AppendText(sFilePath);
			try
				{
				string logLine = System.String.Format(
					"{0:G}: {1}.", System.DateTime.Now, msg);
				sw.WriteLine(logLine);
				}
			finally
				{
				sw.Close();
				}
			}

LogMessage("Problem with program");