[amibroker] Exit if trade not in profit after x amount of days

[jab901]

Can anyone help me code this exit into my trend following system?

I have a simple moving average crossover system. Just need an exit if the 
position is not showing a profit after x days. so:

Buy = Cross(fast, slow) ;
Sell = Cross(slow, fast)// or if position is not profitable after 15 days//

Thanks