I haven't tried HitTest() yet
In which case HitTest() probably returns -1 for nothing?
The debug shows the first listbox as -203 (getid) and the second as -204.
For every control you make, you can assign a unique Id. You can use this in the event system to refer to a specific control by its id. This is especially useful when a number of events use the same callback function. (otherwise, you might not care about assigning a unique id to a control that uses its own callback function).
If you don't assign an id to a control, one is assigned for you, for internal use, but your application can just assume that value is wxID_ANY.
In wxFormBuilder, you can set your Id in the properties for the control, by giving it a name, which will be made into a Const variable by wxCodeGen.
For example, you make the id something like ID_BORIS, and you'll have that generated as a Const with a unique int value.
You could then, in a shared callback method have something like :
Select event.GetId() Case ID_BORIS Debuglog "You clicked on Boris!" Case ID_FRED Debuglog "You clicked on Fred!" End Select