Text box that autopopulates

[Dugantrain]

I have an invisible text box on a subform that is a foreign key in a table. The primary key that it relates to is an Autonum on the main form and I need the text box on the subform to autopopulate with the same number as the text box on the main form. Any clue as to how to do this?

 

[Rob.Mills]

In the subform you can tell it which field for the child and master fields and that will do what you're looking for.