{
  TCanvas *canvas = new TCanvas("mycanvas","mycanvas",2,2,800,400);
  canvas->cd();
  TPad *pad1 = new TPad("LeftPad","LeftPad",0.3,0.1,0.55,0.9);
  pad1->Draw();
  TPad *pad2 = new TPad("RightPad","RightPad",0.65,0.1,0.9,0.9);
  pad2->Draw();
  canvas->cd();
  TButton *b1 = new TButton("SelectPad1","pad1->cd();",0.05,0.1,0.25,0.45);
  b1->SetTextSize(0.2);
  b1->Draw();
  TButton *b2 = new TButton("SelectPad2","pad2->cd();",0.05,0.55,0.25,0.9);
  b2->SetTextSize(0.2);
  b2->Draw();
  canvas->Modified();
  canvas->Update();
  pad1->cd();
}