how to delte minimize and max button in right upper!

BOOL CMainFrame::PreCreateWindow(CREATESTRUCT& cs)
{  
 cs.style &= ~(WS_MINIMIZEBOX|WS_MAXIMIZEBOX);
 //cs.style|=WS_MAXIMIZEBOX;
 if( !CFrameWnd::PreCreateWindow(cs) )
  return FALSE;
 // TODO: Modify the Window class or styles here by modifying
 //  the CREATESTRUCT cs
   
 return TRUE;
}