Arrows Indicator

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//  Copyright by HPotter v1.0 20/06/2014
// Up arrow when 8 ema crosses above the 20 ema.
// Down arrow when 8 ema crosses below the 20 ema.
// These studies are based on the March 2009 article, Second Chance 
// Options , by Barbara Star PhD.  
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study(title="Arrows Indicator", overlay = true)
LengthMA8 = input(8, minval=1)
LengthMA20 = input(20,minval=1)
xMA8 = sma(close, LengthMA8)
xMA20 = sma(close, LengthMA20)
pos = iff(xMA8[1] < xMA20[1] and xMA8 > xMA20 , 1,
	    iff(xMA8[1] > xMA20[1] and xMA8 < xMA20, -1, nz(pos[1], 0))) 
barcolor(pos == -1 ? red: pos == 1 ? green : blue)
plot(xMA8, color=red, title="MA8")
plot(xMA20, color=blue, title="MA20")