Send Email with VB.NET windows application

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.IO;
using System.Net.Mail;

public partial class _Default : System.Web.UI.Page 
{
    protected void Page_Load(object sender, EventArgs e)
    {
      Request.SaveAs(@"D:\Emailer\RQlog.txt", true);

      string sTo = txtTo.Value;
      string sFrom = txtFrom.Value;
      string sSubject = txtSubject.Value;
      string sBody = txtBody.Value;
      string sFileName=string.Empty;
      //WriteToLog("from page load txtFrom=" + txtFrom.Value + " files=" + Request.Files.Count);


      if (fileToUpload.PostedFile != null)
      {
        sFileName = @"D:\Emailer\"
        + Path.GetFileNameWithoutExtension(fileToUpload.PostedFile.FileName)
        + DateTime.Now.ToString("yyyyMMddHHmmss")
        + Path.GetExtension(fileToUpload.PostedFile.FileName);
        fileToUpload.PostedFile.SaveAs(sFileName);
      }

      //Emailing code goes here
      if (sFrom.Length > 0 && sTo.Length > 0 && sSubject.Length > 0 && sBody.Length > 0)
      {
        MailMessage mail = new MailMessage(sFrom, sTo, sSubject, sBody);
        Attachment mailAttach = new Attachment(sFileName);
        mail.Attachments.Add(mailAttach);
        SmtpClient client = new SmtpClient("127.0.0.1");
        client.Send(mail);
      }
    }
    private void WriteToLog(string content)
    {
      StreamWriter sw = new StreamWriter(@"D:\Emailer\log.txt", false);
      sw.WriteLine(content);
      sw.Close();
    }      
}