#include 

using namespace wkgl;

//Callback prototypes
BOOL OnButton( Component*, UINT, WPARAM, LPARAM );

WPARAM main()
{
  Window win( "My Second Window" );
  Button button( "Test Button", 0, 0 );
  
  //Add the button to the window.
  win.add( &button );

  //Add the callback for the button
  button.addCallBack( OnButton );

  //Show the window
  win.show();
     
  return win.beginMessageLoop();
}

//Callback for button
BOOL OnButton( Component *com, UINT message, WPARAM wParam, LPARAM lParam )
{
  static char buf[50];      //Buffer for buttons text.
  static int  clicked;      //Number of times the button has been clicked

  if ( message == BN_CLICKED )
  {
   sprintf( buf, "You clicked the button: %i times", ++clicked );
      
    //Set the button's text.
    ((Control*)com)->setText( buf );

    return TRUE;
  }
  
  return FALSE;
}

    Source: geocities.com/mike_nooner/docs/doc/Tutorials/samples

               ( geocities.com/mike_nooner/docs/doc/Tutorials)                   ( geocities.com/mike_nooner/docs/doc)                   ( geocities.com/mike_nooner/docs)                   ( geocities.com/mike_nooner)