Plotting Profit Target & Stop Loss Prices

[SystemTrading]

I am sending my profit target and stop loss orders via the OnExecution() method. When my entry is filled I send GTC stop and profit target orders. I want to plot a horizontal line at these prices for as long as I am in the trade. What is the best way to do this? I don't see a way to just extend a line once drawn but I think there has to be a better way then to draw a new line every bar.

[NinjaTrader_JoshP]

You can just use DrawHorizontalLine() and it will extend infinitely left and right. Remove the line when you are done with the trade.