indicator("Double Moving Average Trading Strategy", overlay=true)

fastLength = input.int(10, title="Fast MA Period")
slowLength = input.int(20, title="Slow MA Period")

fastMA = ta.sma(close, fastLength)
slowMA = ta.sma(close, slowLength)

plot(fastMA, title="Fast MA", color=color.blue)
plot(slowMA, title="Slow MA", color=color.red)

if (ta.crossover(fastMA, slowMA))
    label.new(bar_index, high, text="Buy", color=color.green)
    alert("Buy at: " + str.tostring(close), alert.freq_once_per_bar_close)

if (ta.crossunder(fastMA, slowMA))
    label.new(bar_index, low, text="Sell", color=color.red)
    alert("Sell at: " + str.tostring(close), alert.freq_once_per_bar_close)