value from a main form to a sub form

[Clivej01]

I have a main form that has a
field
name client id
with a value from the client details table

there is a subform on this form which is linked by the invoice number. When i create a ne record the invoice number is copied into the new record but the client ID is not.

Can this be fixed

I have very little programming experience to a well annotated responce would be helpful.

Regards