3 subforms with totals needed on main form

[jmh944911]

I thought I knew how to do this but I guess not.
I have a form with 3 sub forms. Each of these subforms has a grandtotal that I want to move to the mainform.

Form is like this:

Formheader
detail
subform1
subform2
subform3
(sf1grandtotal + sf2grandtotal)/sf3grandtotal = displayvalue
Formfooter

I thought all it would take was an explicit reference
(=Forms![subform1]!Textbox1)
to the subforms from the main form. However, that generates "#Name?" in my text box where I wish to display the value.

Any assistance is welcome. If I have missed a post in my search that covers this please let me know the post.
Thank you.

 

[pbaldy]

http://www.mvps.org/access/forms/frm0031.htm