initial creation of key field in child from parent key
i have a "child" table in which i want the key to be automatically set up from the parent record that is currently active. So the user either selects an existing record or creates a new master record in the master table. After that record is chosen, the primary key needs to automatically be put into the "child" file foreign key. I am new and not sure how to hold the data to pass it along. any help would be appreciated.