virtual void  LeftDown(Point, dword);
	virtual void  LeftUp(Point, dword);
	virtual void  MouseMove(Point, dword);
	virtual void  MouseLeave(Point, dword);

void LeftDown(Point p, dword keyflags)
{
   SetCapture(); 
   // All mouse events are now directed to this ctrl until ReleaseCapture is called
}

void MouseMovePoint p, dword keyflags)
{
   if (HasCapture())
      // Left mouse is depressed
   else
      // No button pressed
}

void LeftDown(Point p, dword keyflags)
{
   ReleaseCapture(); 
}