C#

dataset.Movie.Clear(); //clear your dataset
oleDbDataAdapter1.Fill(dataset); //refill your dataset
if ( dataset.Movie.Count>0) // check to see if the dataset is empty
{
 comboBox1.Text=dataset.Movie[0].Title; // I have just titles in my combobox
}
else
{
 comboBox1.Text="Sorry Jack No Data is in the Database!";
 comboBox1.Enabled=false; // you can later enable it when you have data
}

csc.exe /t:exe /r:MyAsm.dll /r:MyApp.exe /out:Test.exe Test.cs

public class KeyboardFilter : IMessageFilter
{
  public bool PreFilterMessage(ref Message m)
  {
    if (m.Msg == 0x0100) // WM_KEYDOWN
      Console.WriteLine("Key down: " + m.WParam.ToString());
    return false;
  }
}

private string ComputeMD5(string value)
{
  MD5 md5 = new MD5CryptoServiceProvider();
  byte[] buffer = Encoding.UTF8.GetBytes(value);
  byte[] cipher = md5.ComputeHash(buffer);
  StringBuilder sb = new StringBuilder(cipher.Length * 2);
  for (int i=0; i<cipher.Length; i++)
    sb.Append(cipher[i].ToString("x2"));
  return sb.ToString();
}