Is there a way to have information a user enters in a Text Field populate a field in the header on subsequent/master pages?
For example, if the form asks for a person's first name in one text field, and last name in another text field, than the person's last name appears in the header of all subsequent pages of the form?
Yes it can be done ....here is a sample. I could not use your sample as it was not built in Designer.
The code to fill the field on the Master Page is on teh calculate event.