void Start(  )
{
	int itMaxNumber = 40;
	
	while( it < itMaxNumber )
	{
		MyDraw(  );
                ProcessEvents();
		it++;
	}
}

void Start()
{
   it = 0;
   SetTimeCallback(-50 THISBACK(MyDraw));
}

void MyDraw()
{
	...
	if (it >= itMaxCount)
		KillTimeCallback();
}