//void PaintArea (TH1 *h, Int_t binl, Int_t binh, Int_t color) 
{
   gROOT->Reset();
   TCanvas * c1 = new TCanvas("c1", "c1", 600, 100, 600, 400);
   TFile f("hsimple.root");
   Float_t from =  0; 
   Float_t to   = 50;
   TFile f1("hnew.root", "RECREATE");
   TH1F * h = new TH1F("threeg", "Three gaussians", 200, from, to);
   TF1 * fg3 = new TF1("fg3", "gaus(0) + gaus(3) + gaus(6)", from, to);
   fg3->SetParName(0, "gc_1");
   fg3->SetParName(1, "gm_1");
   fg3->SetParName(2, "gs_1");
   fg3->SetParName(3, "gc_2");
   fg3->SetParName(4, "gm_2");
   fg3->SetParName(5, "gs_2");
   fg3->SetParName(6, "gc_3");
   fg3->SetParName(7, "gm_3");
   fg3->SetParName(8, "gs_3");

   fg3->SetParameter(0, 5);
   fg3->SetParameter(1, 10);
   fg3->SetParameter(2, 4);
   fg3->SetParameter(3, 3);
   fg3->SetParameter(4, 20);
   fg3->SetParameter(5, 2);
   fg3->SetParameter(6, 1);
   fg3->SetParameter(7, 30);
   fg3->SetParameter(8, 7);
 
   for (Int_t i=0; i < 1000; i++) {
     h->FillRandom("fg3");
   } 
   h->Draw();
   h->SetFillStyle(1001);
   h->SetFillColor(94);


   Int_t binl = 65;
   Int_t binh = 100;
   Int_t color = 4;
   Int_t colora = 7;
   h->Draw();
//   printf("%d %d %d\n", bin, color, h->GetBinContent(bin));
   Int_t nbins = binh - binl + 1;
   TGraph * pl  = new TGraph(2 * nbins + 3);
   Int_t ip = 0;
   Axis_t ymin = h->GetYaxis()->GetXmin();
   for (Int_t bin = binl; bin <= binh; bin++) {
      pl->SetPoint(ip, h->GetBinLowEdge(bin), h->GetBinContent(bin));
      pl->SetPoint(ip + 1 , h->GetBinLowEdge(bin) + h->GetBinWidth(bin), 
                            h->GetBinContent(bin));
      ip += 2;
   }
   pl->SetPoint(ip, (pl->GetX())[ip-1], ymin);
   pl->SetPoint(ip+1, (pl->GetX())[0], ymin );   
   pl->SetPoint(ip+2, (pl->GetX())[0], (pl->GetY())[1]);   
   pl->SetFillColor(color);
   pl->Draw("LF");
   c1->Modified();
   c1->Update();
//   c1->Print("cblue.gif");
//   pl->SetFillColor(colora);
//   c1->Modified();
//   c1->Update();
//   c1->Print("ccyan.gif");
   h->GetListOfFunctions()->Add(pl, "LF");
   h->Write();
// let it blink in 0.3 sec
   for (Int_t i = 0; i < 100; i++) {
      if (gSystem->ProcessEvents())
         break;
      gSystem->Sleep(200);
      pl->SetFillColor(colora);
      c1->Modified();
      c1->Update();
      if (gSystem->ProcessEvents())
         break;
      gSystem->Sleep(200);
      pl->SetFillColor(color);
      c1->Modified();
      c1->Update();
      if (gSystem->ProcessEvents())
         break;
  }

}