anchor.diff:  
       FSliderLength := Trunc(area * SliderSize);
       //FSliderLength := Trunc((width/area) * (fmax /area  ));
  -    if FSliderLength < 20 then
  -      FSliderLength := 20;
  +    if FSliderLength < cMinSliderLength then
  +      FSliderLength := cMinSliderLength;
       if FSliderLength > area then
         FSliderLength := area;
       area := area - FSliderLength;
  
positive.code:   SliderSize    := 0.5;
    FOnScroll     := nil;
    FSliderPos    := 0;
    FSliderLength := 10;
    FScrollStep   := 1;
    FPageSize     := 5;
    FLargeChange  := 0;
  
negative.code: 
  implementation
  
  const
    cMinSliderLength = 20;
  
  { TfpgScrollBar }
  
  constructor TfpgScrollBar.Create(AOwner: TComponent);
  