In Informatic 0 or NULL supposed have the same value. 
With Amibroker is not true 
  
In the formula Below 
on the line 9 and 14  
If I'm use a 0(zero), I'm obtain a graphe who have a PBC on 50% of the screen 
If I'm use a NULL, I'm obtain a graphe who have a PBC on 100% of the screen 
  
Made attention to that when you write a formula 
  
YLTech 
  
  
------------------------------------ 
_SECTION_BEGIN("BUG on 0 or NULL"); 
SetChartOptions (0,chartShowArrows|chartShowDates);
_N (Title = StrFormat("{{NAME}} - {{INTERVAL}} {{DATE}} Open %g, Hi %g, Lo %g, Close %g (%.1f%%) {{VALUES}}", O, H, L, C, SelectedValue( ROC( C, 1 ) ) ));
Plot ( C, "Close", ParamColor("Color", colorBlack ), styleNoTitle | ParamStyle("Style") | GetPriceStyle() ); 
Haut=  IIf(Interval()==3600, Ref(HHV(C,20),-1),
IIf(Interval()==1800, Ref(HHV(C,40),-1),
IIf(Interval()==900, Ref(HHV(C,80),-1), 
0 /* 0 or Null NOT THE SAME FOR THE GRAPHE */ ))) ; 
Bas=  IIf(Interval()==3600, Ref(LLV(C,10),-1),
IIf(Interval()==1800, Ref(LLV(C,20),-1),
IIf(Interval()==900, Ref(LLV(C,40),-1),
0 /* 0 or Null NOT THE SAME FOR THE GRAPHE */ ))) ; 
Plot (Haut,"HautP",colorBlue,styleLine);
Plot (Bas,"BasP",colorRed,styleLine);
_SECTION_END (); 
------------------------------------ 
  
Merci   YLTech ( Yves L. )   Le présent message et les documents qui y sont joints sont réservés exclusivement au destinataire indiqué. Il est strictement interdit d'en utiliser ou d'en divulguer le contenu. Si vous recevez le présent message par erreur, veuillez le détruire S.V.P. et nous en aviser immédiatement afin que nous puissions corriger nos dossiers. Merci.   This message and the attached documents may contain privileged or confidential information that are intended to the addressee only. Any unauthorized disclosure is strictly prohibited. If you happen to receive this message by error, please delete it and notify us immediately so that we may correct our internal records. Thank you.   yltech@xxxxxxxxxxxx    |