Donchian Fibonacci Support / Resistance

study("Donchian Fibonacci Support / Resistance", shorttitle="Don FIB S/R", overlay=true)
lookback = input(20, title="Lookback", type=integer)
fibLevel1 = input(0.618, title="Fibonacci Level 1", type=float)
fibLevel2 = input(0.382, title="Fibonacci Level 2", type=float)
showDon = input(false, title="show Donchian Channel", type=bool)

donTop = highest(high,lookback)
donBot = lowest(low,lookback)

fib1 = ((donTop-donBot) * fibLevel1) + donBot

fib2 = ((donTop-donBot) * fibLevel2) + donBot

p1 = plot(fib1, color=silver, title="Fib 1")
p2 = plot(fib2, color=silver, title="Fib 2")
plot(showDon ? donTop : na, color=blue, title="Don Top")
plot(showDon ? donBot : na, color=blue, title="Don Bot")

fill(p1,p2,gray, title="Fib Area")