void div2()
{
   gStyle->SetOptStat(0);
   gStyle->SetPadTopMargin(0.);
   gStyle->SetPadBottomMargin(0.);
   gStyle->SetPadLeftMargin(0.);
   gStyle->SetPadRightMargin(0.); 
   TCanvas* mCanvas = new TCanvas("kt","kt",500,700);
   Double_t mlb = 0.3;
   Double_t mrt = 0.1;
   Double_t nx  = 4;
   Double_t ny  = 5;
// Double_t nx  = 1;
// Double_t ny  = 3;
   
   DividegPad(nx,ny,mlb,mrt,mrt,mlb);

   mHisto = new TH1D("Rside","Rside",6,0.01,0.59) ;
   for(Int_t i=1 ; i<=nx*ny; i++) {
      mCanvas->cd(i) ;
      mHisto->Draw() ;
   }
} 

void DividegPad(Int_t nx, Int_t ny,
                Float_t l, Float_t r, Float_t t, Float_t b)
{
   Int_t ix, iy, n=0;
   Double_t x1, x2, y1, y2;
   Double_t dx = ((1-r)*(1-l))/((1-r)*(1-l)*(nx-2)-r+2-l);
   Double_t dl = dx/(1-l);
   Double_t dy = ((1-t)*(1-b))/((1-t)*(1-b)*(ny-2)-t+2-b);
   Double_t db = dy/(1-b);
   char *name  = new char [strlen(gPad->GetName())+6];

   y1 = 0;
   y2 = db;
   for (iy=0; iy<ny; iy++) {
      x1 = 0;
      x2 = dl;
      for (ix=0;ix<nx;ix++) {
         if (x1 > x2) continue;
         n++;
         sprintf(name,"%s_%d",gPad->GetName(),n);
         pad = new TPad(name,name,x1,y1,x2,y2,0);
         if (ix==0)    pad->SetLeftMargin(l);
         if (ix==nx-1) pad->SetRightMargin(r);
         if (iy==ny-1) pad->SetTopMargin(t);
         if (iy==0)    pad->SetBottomMargin(b);
         x1 = x2;
         if (ix==nx-2) x2 = 1;
         else          x2 = x1+dx;
         pad->SetNumber(n);
         pad->Draw();
      }
      y1 = y2;
      if (iy==ny-2) y2 = 1;
      else          y2 = y1+dy;
   }
}