public override void ShowDropWindow()
 {
     if (!bDropWindowOpened)
     {
         bDropWindowOpened = true;
         DropWindow dw = new DropWindow();
         dw.Result     += new StringsEventHandler(dw_Result);
         dw.FormClosed += new FormClosedEventHandler(dw_FormClosed);
         dw.Show();
         Rectangle taskbar = NativeMethods.GetTaskbarRectangle();
         if (Engine.ConfigUI.LastDropBoxPosition == Point.Empty)
         {
             dw.Location = new Point(SystemInformation.PrimaryMonitorSize.Width - dw.Width - 100,
                                     SystemInformation.PrimaryMonitorSize.Height - taskbar.Height - dw.Height - 10);
         }
         else
         {
             dw.Location = Engine.ConfigUI.LastDropBoxPosition;
         }
     }
 }