#include "graphics.h"
int getvisualpage(void);
 

The getvisualpage function is available in the winbgim implementation of
BGI graphics. getvisualpage gets the page number of the currently visable
page (which is visible on the screen).
The visual graphics page might not be the one where drawing currnetly
takes place.
The original winbgi was designed to support up to 16 pages, but I have
only used pages 1 and 2 myself. NOTE: Using page number 0 might mess up
the colors. I use pages 1-2 for double buffering.

getactivepage setvisualpage swapbuffers

  no output of example at the moment
  do not hesitate and add it...