Soma
Unless you have some very specific reason (other than whimsy) for using unbound forms that can't be addressed in another manner, I suggest you use bound forms and save considerable time and trouble.
What version of Access and VBA you are using will determine the exact code.
Also whether you are providing your own primary keys or leaving it to the table's autonumber field will impact the code?
You will need to append (see append queries) the record in the main form to the appropriate table, then retrieve or assign the primary key of the appended record. With the PK in hand, you can then loop through records in the subforms and append them. The crux will be to make sure your records stay related.
Cheers,
Bill