I'm not sure I understand you. You can't have a "main form on a tabbed
page". Any form embedded in another form, whether it is on a tab control
page or not, is a SUBFORM.
Do you mean that you have a tab control on your MAIN form, where one page
contains data fields from your main form's Recordset and another page
contains a linked subform?
If so, then all you need to do is set focus to the subform (either using the
mouse or with code) after adding the record to your main form, and go from
there.
If, on the other hand, you have TWO subforms, one listing the records on the
"one" side of a one-to-many relationship, and the other listing the related
"many" records, then you can add a hidden textbox named txtLink to your main
form (not the first subform) with the following ControlSource:
=[Subform1].Form![name of primary key field]
Then, for your second subform, set LinkMasterFields to txtLink, and set
LinkChildFields to the name of the foreign key field in your many-side
table.
