Sử dụng Amibroker AFL for Moving Average trading with buy sell signal

code :

_SECTION_BEGIN("Price");
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", colorDefault ), styleNoTitle | ParamStyle("Style") | GetPriceStyle() );
_SECTION_END();

_SECTION_BEGIN("MA_CROSS");
p = Optimize("PERIOD 1",Param("PERIOD 1",10,2,30,1),2,20,2);
q = Optimize("PERIOD 2",Param("PERIOD 2",90,10,200,10),10,100,10);
y = Optimize("MAType 1",Param("MAType 1",2,1,8,1),1,8,1);
z = Optimize("MAType 2",Param("MAType 2",2,1,8,1),1,8,1);

m=0;    if (y==1) m    =    MA(C,p);  
else    if (y==2) m    =    EMA(C,p);  
else    if (y==3) m    =    DEMA(C,p);  
else    if (y==4) m    =    TEMA(C,p);  
else    if (y==5) m    =    WMA(C,p);  
else    if (y==6) m    =    HMA(C,p);  
else    if (y==7) m    =    Wilders(C,p);  
else    if (y==8) m    =    LinearReg(C,p);

n=0;    if (z==1) n    =    MA(C,q);  
else    if (z==2) n    =    EMA(C,q);  
else    if (z==3) n    =    DEMA(C,q);  
else    if (z==4) n    =    TEMA(C,q);  
else    if (z==5) n    =    WMA(C,q);  
else    if (z==6) n    =    HMA(C,q);  
else    if (z==7) n    =    Wilders(C,q);  
else    if (z==8) n    =    LinearReg(C,q);
Plot(m," MA",IIf(m < Ref(m,-1),colorBlue,colorRed),styleThick);
Plot(n," MA",IIf(n < Ref(n,-1),colorBlue,colorRed),styleThick);

Buy  = Cross(m,n);
Sell = Cross(n,m);
Buy = ExRem(Buy,Sell);
Sell = ExRem(Sell,Buy);
Short = Sell; Cover = Buy;
PlotShapes(Buy+2*Sell,colorWhite,0,IIf(Buy,L,H));
SetPositionSize(1,4);
_SECTION_END();