procedure TForm1.FormClick(Sender: TObject);
begin
     ShowMessage('Sender = '+(Sender as TComponent).Name);
end;

procedure TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var p:TPoint;
    g:TGridCoord;
begin
     p.X := X;
     p.Y := Y;
     p := Form1.ClientToScreen(p);
     p := DBGrid1.ScreenToClient(p);
     g := DBGrid1.MouseCoord(p.X,p.Y);
     ShowMessage(IntToStr(g.X)+' '+IntToStr(g.Y)+# 13 +IntToStr(p.X)+' '+IntToStr(p.Y)+# 13 +IntToStr(DBGrid1.Width)+' '+IntToStr(DBGrid1.Height));
end;