Best way to read in a rolling log file in .NET?

Object mLogLock = new Object(); //to make logging thread safe
    string mLogFile = ""; //set your log location
    string mLogDirectory = "";
    public void HandleMessage(string inMessage)
    {

        lock (mLogLock)
        {
            if (!System.IO.Directory.Exists(mLogDirectory ))
            {
                System.IO.Directory.CreateDirectory(mLogDirectory );
            }

            String theMessage = DateTime.Now.ToString("s");
            if (inMessage != null)
                theMessage += " : " + inMessage;

            StreamWriter sw = new StreamWriter(mLogFile, true);

            sw.WriteLine(theMessage );

            sw.Dispose();
            sw.Close();
        }
    }