Linked Forms

I created two linked forms via the form wizard. I work
for a University. My first form contains the student
name and personal data. The subform shows any contact
that has been made with that student by date of contact.

In the past, I have set up these forms where you can see
the contact data below the student data. Whenever you
added a new contact record the student ID automatically
populated.

The one I am having a problem with now is set up as a
linked form. In other words, the subform (or Linked
form) appears as a button. You have to click on it to
see the contact information.

The problem I am having is that when you are viewing the
contact resords for that student and you click the * to
add a new contact record, you must choose the student id
from a drop down list. I would like the ID to fill in
automatically.