private void FormProgramLinks_Closing(object sender, System.ComponentModel.CancelEventArgs e)
 {
     if (changed)
     {
         try {
             //Let HQ know the program link change.
             Programs.SendEnabledProgramsToHQ();
         }
         catch (Exception ex) {
             ex.DoNothing();
         }
         DataValid.SetInvalid(InvalidType.Programs, InvalidType.ToolBut);
     }
 }