Setting a trailing stop.

Im sure this is a simple question but i havent managed to do it. 

Im trying to set a trailing stop to a possition when its opend. 

It is my understaning from examaning the API refrance explorer that to set it you using 

public bool HasTrailingStop{ get; }

ExecuteMarketOrder(TradeType.Buy, Symbol, 10000, "myLabel", 10, 10, 2, "comment", true);
Print("Position was opened, has Trailing Stop = {0}", result.Position.HasTrailingStop);

This doesnt build however. In effect I want the code to not use stop loss or take profit but instead use a trailing stop with a 10 pip spead. 

Any help would be much appricatied,

WILL