[amibroker] How to place TRAIL stop order using Interactive Broker Controller with Amibroker

[younggundam]

If I want to palce a TRAIL stop order using Amibroker through IB 
controller, what are the numbers I should put for the limitPrice and 
stopPrice: ibc.PlaceOrder( Name(), "Sell", 100, "TRAIL", ?, ?, "Day", 
True ); Suppose the trail amount is $0.50 and I want sell market if 
the trail stop trigger.

Thanks a lot,

Guangdam