TCanvas *canvas;
TH1F    *h;

void CanvasTest()
{
  h      = new TH1F("hist",    "Histo", 10, 0., 10.);
  canvas = new TCanvas("canv", "Canvas", 0, 0, 800, 400);
  canvas->Divide(2, 1);
  canvas->cd(1);
  h->Draw();
  gPad->Print("puppa1.C");
  canvas->cd(2);
  h->Draw();
  gPad->Print("puppa2.C");
  canvas->cd(0);
  gPad->Print("puppa.jpg");
}