My example is not quite as you'd want it - but here it is:
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asiSelectNet('net ?form abVDCform)
In my case, I don't actually want the form to appear - so I'm creating the form to keep everything happy - but the idea is that whatever variable you are using to store your form in needs a property called asiSession storing the asi session id. When asiSelectNet is called, it will either use the specified form, or the current form (I think) to identify the "asiSession".
So you need to add a property called asiSession to your form.
I'm a bit rushed to put together a more complete example. There's one in solution 11256686 though.