[amibroker] Show Donchian Channel on Chart

[electricwally77]

Hello, I'm trying to show the 30 period donchian channel on my chart.
The code seemed to run okay but I'd like to see the price channel
displayed on my chart. Appreciate the help. The code is listed below.

pds=30;
DonchianUpper =HHV(Ref(H,-1),pds);
DonchianLower = LLV(Ref(L,-1),pds);
DonchianMiddle = (DonchianUpper+DonchianLower)/2;

Plot(DonchianUpper,"DU",colorBlue,styleLine);
Plot(DonchianMiddle,"DM",colorGreen,styleLine);
Plot(DonchianLower,"DL",colorRed,styleLine); 

pds=30;
Buy = H > Ref(HHV(H,30),-1);
BuyPrice = Ref(HHV(H,30),-1);
Sell = L < Ref(LLV(L,30),-1);
SellPrice = Ref(LLV(L,30),-1);

Buy = ExRem(Buy,Sell);
Sell = ExRem(Sell,Buy);