It's a little unclear what you want. I'll focus on the description about users entering data, though you could be asking about a more efficient way to allow entry in TextfieldA.
When you say the users have to enter the same information in Form B, does that mean you want to make them double-type the information to be sure they entered the correct information? Or are you trying to build a user friendly application where after they enter information in form A it automatically populates to form B?
In either case, you're looking at using either the BeforeUpdate event on textfieldB (if you want to make sure they entered the same value and error if not) or AfterUpdate event on textfieldA (if you want to auto-populate formB).
What you need to know is how to reference the field of the other form. This is done using the Forms collection, as follows:
E.g. Forms("FormB").TextfieldB to for the AfterUpdate event situation.
One thing that you'll probably want to do is be sure that the other form is open. This can be done by checking
If CurrentProject.AllForms("formname").IsLoaded Then
Not that it's my business, but why do you have two forms that display the same information opened at the same time? If they are so related, why not make one of them the master form and the other a subform?
Randall J Weers
Membership Vice President
Pacific NorthWest Access Developers Group