MACD error HELP ME

Hi all kindly help me with this particular error in MACD

SetChartOptions(0,chartShowDates|chartWrapTitle,chartGridMiddle=0);

Error 55. Invalid assignment. The identifier is read-only (constant) and can not be written to.


Forumula is here


FormulaName = "PE - MACD Modified";

SetChartOptions(0,chartShowDates|chartWrapTitle,chartGridMiddle=0);
GraphXSpace = 10;
#pragma nocache
#include_once <\PEInc\PatternExplorer_f0.afl>
#include_once "C:\Program Files (x86)\AmiBroker\Formulas\PatternExplorer\#Defaults & Mods\PE - Defaults.afl"
#include_once "C:\Program Files (x86)\AmiBroker\Formulas\PatternExplorer\#Defaults & Mods\PE - Mods.afl"
/*******************************************************************************************/
AddCustomCodeBeforePE();
/*******************************************************************************************/
AddAlertParam(def_AudioAlert,def_EmailAlert,def_BarComplete);
/*******************************************************************************************/
_SECTION_BEGIN("Alerts");
BuySig = ParamList("Buy Signal", List1 = "MACD crosses Signal,MACD crosses zero Level",0);
SellSig = ParamList("Sell Signal",List2 = "Signal crosses MACD,MACD crosses zero Level",0);
for( i=0; i<10; i++) {if( StrExtract(List1, i) == BuySig ) BuySignal = i+1; }
for( i=0; i<10; i++) {if( StrExtract(List2, i) == SellSig ) SellSignal = i+1; }
_SECTION_END();
/*******************************************************************************************/
_SECTION_BEGIN("Main Parameters");
AddAvgTypeParam(1);
r1 = Param( "Fast Average", 6, 2, 100, 1 );
r2 = Param( "Slow Average", 13, 2, 100, 1 );
r3 = Param( "Signal Average", 5, 2, 100, 1 );
_SECTION_END();
/*******************************************************************************************/
_SECTION_BEGIN("Styles");
MACDstyle = ParamStyle("MACD",styleThick);
Signalstyle = ParamStyle("Signal",styleThick);
Histostyle = ParamStyle("Histogram",styleHistogram,maskAll);
_SECTION_END();
/*******************************************************************************************/
_SECTION_BEGIN("Colors");
MACDcolor = ParamColor("MACD", def_MACDcolor);
Signalcolor = ParamColor("Signal", def_Signalcolor);
Histocolor = ParamColor("Histogram", def_Histocolor);
_SECTION_END();
/*******************************************************************************************/
MACD_mod = Average(C,r1,AvgType) - Average(C,r2,AvgType);
MACDsignal_mod = Average(MACD_mod,r3,AvgType);
MACDHistogram_mod = MACD_mod-MACDsignal_mod;
/*******************************************************************************************/
AddGradientBackground(def_BGColorswitch,def_BgTopcolor,def_BgBottomcolor,def_titlebkcolor);
/*******************************************************************************************/
Plot(MACD_mod, StrFormat(_SECTION_NAME()+"(%g,%g)", r1, r2),MACDcolor,MACDstyle);
Plot(MACDsignal_mod, "Signal" + _PARAM_VALUES(),Signalcolor,Signalstyle);
Plot(MACDHistogram_mod, "MACD Histogram",Histocolor,Histostyle);
/*******************************************************************************************/
Buy = def_Buy AND IIf(BuySignal==1,Cross(MACD_mod,MACDsignal_mod),Cross(MACD_mod,0));
Sell = def_Sell AND IIf(SellSignal==1,Cross(MACDsignal_mod,MACD_mod),Cross(0,MACD_mod));
Filter = def_Filter AND NOT GroupID()==253;
Filter = Filter AND (Buy OR Sell);
Addefaultcolumns();
Adddefaultcolumns(2,1);
AddTextColumn(FullName(),"Full name");
/*******************************************************************************************/
Alerttext =
"\n, MACD = "+ WriteVal(MACD_mod)+", "
+"\n, Signal = "+WriteVal(MACDSignal_mod);
AddAlert(Buy,Audio,Email,BuySig + Alerttext,1,BarComplete,def_BuySound1);
AddAlert(Sell,Audio,Email,SellSig + Alerttext,2,BarComplete,def_SellSound1);
/*******************************************************************************************/
ToolTip = def_ToolTip;
/*******************************************************************************************/
AddCustomCodeAfterPE();
/*******************************************************************************************/
Title = "PatternExplorer.com - MACD Modified "+AvgText + " - " + Name() + " - " + EncodeColor(colorRed)+ Interval(2) + EncodeColor() + " " + Date() + ", "+EncodeColor(colorRed) +"MACD("
+WriteVal(r1,1.0)+","+WriteVal(r2,1.0)+") = "
+WriteVal(MACD_mod,1.2)+","+EncodeColor(Signalcolor)+" Signal("+ WriteVal(r1,1.0)+","
+WriteVal(r2,1.0)+","+WriteVal(r3,1.0)+") = "+WriteVal(MACDSignal_mod,1.2)+" ";
_SECTION_BEGIN("Buy Sell Arrows");
shapesSignalswitch = ParamToggle("Cross Signal Arrows","On,Off");
UPcolor = ParamColor( "UP Color", colorGreen );
DOWNcolor = ParamColor( "Down Color", colorRed );
Buy=Cross( MACD(), Signal() );
Sell=Cross( Signal(), MACD() );
shape = Buy * shapeUpArrow + Sell * shapeDownArrow;
PlotShapes( IIf(shapesSignalswitch,-1e10,shape), IIf( Buy, UPcolor, DOWNcolor ));
//PlotShapes( IIf( Buy , shapeSmallCircle, shapeNone ), colorWhite, 0, Graph1 , 0 );
//PlotShapes( IIf( Sell , shapeSmallCircle, shapeNone ), colorRed, 0, Graph1 , 0 );

//PlotShapes( IIf( Buy , shapeCircle, shapeNone ), colorWhite, 0, Graph1 , 0 );
//PlotShapes( IIf( Sell , shapeCircle, shapeNone ), colorRed, 0, Graph1 , 0 );

_SECTION_END();


Plot(0,"",colorWhite,styleLine|styleThick);

This is human error:-

get ride of the =0;

Read the help guide properly.

chartGridMiddle is a internal contant.

thanks kevin about to post error resolved anyways thanks a lot