Run method in parent window

I have a ListBox where I open a New FormWindow for editing the record, but as the data changes I would like to run a ‘ReLoad ListBox Data’ Method in the Parent window. How do I do that?

All I get from the IDE is 'Variant has no Method …

you could define and raise a event, you need AddHandler and register a method for this event.
or you need that reference to this window and a public method.