This is a design pattern issue. According to what I've read, you should create an interface to describe the classes the worker could be part of. Maintenance is far easier if the class always has the same signiture. So there is nothing you would need to change in the calling program if you add another class the worker can be part of.

PF

>In VFP, if I needed to instaniate classes of different types I would do something like this:
>

>define class Myclass as session
>  worker = null
>
>  proc init(cworker)
>     do case
>       case cworker = "A"
>         this.worker = createobject("ClassA")
>       case cworker = "B"
>         this.worker = createobject("ClassB")
>      endcase
>   endproc
>enddefine
>

>
>My problem is that because C# is strongly typed, I don't know how to make worker be an instance of one of several different classes. Any suggestions?