ASP.NET(Write txt log file in daily basis)

public static void WriteLog(string strError, string MethodName, string parameters, string pageName)

    {

        string FileName = HttpContext.Current.Server.MapPath("Path/logs_" + DateTime.Now.ToString("yyyyMMdd") + ".txt");

        string strText = DateTime.Now.ToString() + "\t" + pageName + "\t\t" + MethodName + "\t" + parameters + "\t" + strError;

        if (!File.Exists(FileName))

        {

            // Create New Text File

            FileStream fStream = new FileStream(FileName, FileMode.Create, FileAccess.Write);

            StreamWriter sw = new StreamWriter(fStream);

            sw.WriteLine(strText);

            sw.Close();

            fStream.Close();

        }

        else

        {

            FileInfo finfo = new FileInfo(FileName);

            while (IsFileLocked(finfo))

            {

                Thread.Sleep(500);

            }

            finfo = null;

            FileStream aFile = new FileStream(FileName, FileMode.Append, FileAccess.Write);

            StreamWriter sw = new StreamWriter(aFile);

            sw.WriteLine(strText);

            sw.Close();

            aFile.Close();

        }

    }

    private static bool IsFileLocked(FileInfo file)

    {

        FileStream stream = null;

        try

        {

            stream = file.Open(FileMode.Open, FileAccess.ReadWrite, FileShare.None);

        }

        catch (IOException)

        {

            //the file is unavailable because it is:

            //still being written to

            //or being processed by another thread

            //or does not exist (has already been processed)

            return true;

        }

        finally

        {

            if (stream != null)

                stream.Close();

        }

        //file is not locked

        return false;

    }