Relative strength with MA - Trendline Investor

study("Relative Strength Comparison", shorttitle="Relative Strength Comparison")
a = tickerid
b = input("Nifty", type=symbol)
as = security(a, period, close)
bs = security(b, period, close)
plot((as/bs)*100, title="Relative Strength Comparison", color=blue)
len = input(52)
plot(ema((as/bs)*100, len), color=red)