problem with Instrument selector

[set2win]

found this code in the forum. I have an object reference not set to an instance error
what im trying to do is have a Instrument selector in the parameters so the user can pick the instrument.
i plan to use the selected value as a string item that will be part of an OIF OrderInstructionFile string.
so I make private string Instrument1;
now i need to assign the selected instrument to Instrument1
FullName
what might i be missing to accomplish this?


[TypeConverter(typeof(NinjaTrader.Gui.Tools.Instrum entSelector))]
[Display(Name="Select Instrument", GroupName = "Parameters", Order = 0)]
public Instrument InstrumentInput
{ get; set; }

protected override void OnStateChange()
{
if (State == State.SetDefaults)
{
InstrumentInput = null;
}
}

[NinjaTrader_Jesse]

Helllo set2win,

Instrument is the only variable that a script would have so you can use Instrument for the instrument that you applied the script to