[amibroker] Please help Add Arrow Buy sell signal

[ihsaham]

Price = (H+L)/2;
CoefLookback = 5;

Coef = (Price-Ref(Price, -1))^2+(Price-Ref(Price, -2))^2+(Price-Ref
(Price, -3))^2+(Price-Ref(Price, -4))^2+(Price-Ref(Price, -5))^2;
Hai All Amibroker AFL expert please help me to add Arrow Buy (Green) 
and Arrow Sell (Red)

Thank you All,
Anthony



SumCoef=0;
SumCoefPrice=0;
for(i=0; i < CoefLookback; i++) {
        SumCoef = SumCoef + Ref(Coef, -i);
        SumCoefPrice = SumCoefPrice + (Ref(Coef, -i) * Ref(Price, -
i));
}
DCEF = SumCoefPrice / SumCoef;

Plot(Close, "Close", colorBlack, styleLine);
Plot(DCEF, "NonLinear Ehlers Filter", IIf(Close>DCEF, colorGreen, 
colorRed), styleLine);


Buy1 = Cross(Close,NLEF);
PlotShapes( shapeUpArrow*Buy1, colorBlack,0,L, -20);

sell1 = Cross(NLEF,Close);
PlotShapes( shapeDownArrow*Sell1, colorRed,0,L, -20);