Working with MDI form

I'm working with MDI forms, the child form is my data form.
I need to know how to open a few child windows, with a diferent recordset.
Every child form represent a recordset.

At the beginning I was using :

Dim frm as new (the form name)
frm.show

but always the child windows that were open, show me the same recordset

I'm expecting for answer, Thank you all