{
  c1 = new TCanvas("c1","White histo",200,10,700,500);            
  c1->SetFillColor(0); 
  c1->GetFrame()->SetFillColor(0); 
  hpx    = new TH1F("hpx","This is the px distribution",100,-4,4);
  hpx->SetFillColor(0); 

  Float_t px,py;
  for (Int_t i = 0; i < 25000; i++) {
  gRandom->Rannor(px,py);
  hpx->Fill(px);
  }
  hpx->Draw();
  c1->SaveAs("white.gif");
}