Rejected trade

I had a trade, placed by my TradeStation system, rejected today, without any notification that it was rejected. Worse yet, the closing trade was sent out by email, when the opening trade was not.

The cause was that a loss on my first trade reduced the available cash in my account, and this was the reason that the second trade was rejected.

There is no way any automatic system can be used with collective2 wntil some answer to this problem is created. I need to be able to say “Use this percentage of my available cash for this trade”, so that collective2 works out the number of contracts I should be trading. That way I can let the trades run with minimal attention. during the trading day.