Two different fields to one text box how?

[eldarbs]

I want to create a text box on a form that will update two different fields from different tables simultaneously how ?
Namely, How can I set the controlsource on the Properties of the textbox for two different fields ??

 

[RainLover]

=[TableA].[FieldA] & " " &[TableB].[FieldB]

This is only good if both are in the Form's Record Source.

You may need to explain more if this does not work.

 

[eldarbs]

its give me an error - #Name?
I have one form that I linked to two tables by a query, one table for customers and another table for sales. the Form has one tab for filling customer data and another tab to fill sales data
Both tables have a field called "Social Security Number" which I want to connect by it the relationship between the tables
so when I fill the number in the form i want it to enter to both tables at the same time