Relative Strength Index

//@version=2
strategy(title="Relative Strength Index", shorttitle="RSI")
slen    = input(55, title="Short length")
llen    = input(126, title="Long length")
sup     = ema(max(change(close), 0), slen)
sdown   = ema(-min(change(close), 0), slen)
rsi1    = sdown == 0 ? 100 : sup == 0 ? 0 : 100 - (100 / (1 + sup / sdown))
lup     = ema(max(change(close), 0), llen)
ldown   = ema(-min(change(close), 0), llen)
rsi2    = ldown == 0 ? 100 : lup == 0 ? 0 : 100 - (100 / (1 + lup / ldown))
ob      = input(55, title="Overbought")
os      = input(45, title="Oversold")
tp      = input(.9, title="Take profit level %")*.01
sl      = input(3, title="Stoploss level %")*.01
mid     = avg(ob,os)
plot    (mid, color=#4f4f4f, transp=0)
hline   (ob, color=#4f4f4f, linestyle=dotted)
hline   (os, color=#4f4f4f, linestyle=dotted)
long    = crossover(rsi1,rsi2)
short   = crossunder(rsi1,rsi2)
vall    = valuewhen(long,close,0)
lexit1  = high>=(vall*tp)+vall
lexit2  = low<=vall-(vall*sl)
vals    = valuewhen(short,close,0)
sexit1  = low<=vals - (vals*tp)
sexit2  = high>=vals + (vals*sl)
bgcolor (color=long?lime:na,transp=50)
bgcolor (color=short?red:na, transp=50)
strategy.entry("Long", strategy.long, when=long)
strategy.close("Long", when=lexit1)
strategy.close("Long", when=lexit2)
strategy.close("Long", when=short)
strategy.entry("Short", strategy.short, when=short)
strategy.close("Short", when=sexit1)
strategy.close("Short", when=sexit2)
strategy.close("Short", when=long)
plot    (rsi1, color=orange, transp=0,linewidth=1, title="Short period RSI")
plot    (rsi2, color=aqua  , transp=0,linewidth=1, title="Long period RSI")