I have created a subform where I will enter customer name & info as part of a main appointment form. My customer table seems to work fine if I manually create a new customer but when I try to create a new customer by entering data into the fields in the subform first I get the error message: You tried to assign the Null value to a variable that is not a variant data type. which seems to be related to the autonumber field in the customer table and then no matter what I do the form wants to move on to the
next new customer and nothing gets saved in the customerID field in the appointment table which  contains
the appointments. When I open the customer table the new customer is there and the autonumber field works fine but I can't figure out why it will not enter the customerid into the appointment table.  Do you have any suggestions?

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Reply from Richard Rost:

You have to have data in the parent form before you can add any data to the subform.