C#

string Format_Date = DateTime.Now.AddMonths(-1).ToString("MM-yyyy");
    String filesaveLocation = null;
    filesaveLocation = Path.Combine(ConfigurationSettings.AppSettings["tLocation"], Format_Date);
    if (!Directory.Exists(filesaveLocation))
    {
        System.IO.Directory.CreateDirectory(filesaveLocation);
        logging.Error("The location " + filesaveLocation + " does not exist.");
        return packageId;
    }

   else
    {
       string[] RFiles = (from path in Directory.GetFiles(filesaveLocation)
                             let name = Path.GetFileName(path)
                             where name.EndsWith(".pdf") ||
                             name.EndsWith(".xlsx") ||
                             name.EndsWith(".xls")
                             select path).ToArray();

     }
        foreach (String RFile in RFiles)
      {
      }

private void Form1_Load(object sender, EventArgs e)
{
    string cifTime = timeCIF.Text;
    string chkCIF = "N";
    emailBody.Text = "Example\nCIF = " + chkCIF + "\nTIME = " + timeCIF.Text;
}

private void updateButton_Click(object sender, EventArgs e)
{
    //There is a combo box on this form and example is the first option
    if (comboInst.Text == "Example")
    {
        //Here is where the check box verification is, if it is true it should change the N to Y
        if (checkCIF.Checked == true)
        {
            //This part needs to update the current contents of the email body. Obviously, this isn't working for me so I commented out some examples I tried...
            //string s = emailBody.Text;
            //string chkCIF = "Y";

            //s = s.Replace("N", chkCIF);

            string theString = emailBody.Text;
            theString.Remove(3, 2).Insert(3, "Y");
        }
    }