void DemoMarkers (HANDLE hLcWnd)
{
  HANDLE hDrw, hBlock, hEnt;
  double x0, y0, x1, y1; 

  // get drawing and block, linked with CAD window
  hDrw = lcPropGetHandle( hLcWnd, LC_PROP_WND_DRW );
  hBlock = lcPropGetHandle( hLcWnd, LC_PROP_WND_BLOCK );
  x0 = 5.0;
  y0 = 15.0;
  x1 = 70.0;
  y1 = 50.0;
  hEnt = lcBlockAddLine( hBlock, x0, y0, x1, y1 );
  lcBlockMarker( hBlock, hEnt, 20.0, L"Start element" );
  lcBlockMarker( hBlock, hEnt, 40.0, L"End element" );
  lcBlockMarker( hBlock, hEnt, 60.0, L"Information" );
  // update view
  lcBlockUpdate( hBlock, LC_TRUE, 0 );
  // zoom extents
  lcWndZoomRect( hLcWnd, 0, 0, 0, 0 );
}