SMA Crossover Signal

This Pine Script plots 5, 20, and 50-period simple moving averages and highlights trade signals. It shades the background green if the price is above the 50 SMA and red if below. A "BUY SIGNAL" appears only when the 5 SMA crosses above the 20 SMA while the background is green, and a "SELL SIGNAL" appears only when the 5 SMA crosses below the 20 SMA while the background is red.