Upload Immagini c# asp.net
[C# ]

private void Upload(Object Source, EventArgs e)
{
  if (myFile.PostedFile != null)
  {
    int intFileLength;
    string ImgFileNamePath;
    string ImgFileName;
    if (myFile.PostedFile.ContentType != "image/pjpeg")
    {
      lbResult.Text = "Tipo di file non valido";
    }
    else
    {
      if (myFile.PostedFile.ContentLength > 2000000)
      {
        lbResult.Text = "File troppo grande";
      }
      else 
      {
        try 
        {
          ImgFileNamePath = myFile.PostedFile.FileName;
          intFileLength = ImgFileNamePath.Length-ImgFileNamePath.LastIndexOf("\\");
          ImgFileName = ImgFileNamePath.Substring(ImgFileNamePath.Length-intFileLength+1);
          myFile.PostedFile.SaveAs(Server.MapPath("image/annunci/small/") + ImgFileName);
            
          lbResult.Text = "File salvato";
        }
        catch (Exception ex)
        {
          lbResult.Text = @"Errore nel salvataggio:
" + ex.Message;
        }
      }
    }
  }
}

//in your form