#Name Error In Form Text Box--passing From Subform

Hi--I am working on a database which is a modification of the following MS Access 2003 Order Management template:
(URL address blocked: See forum rules)=CT101426031033

In my database, I have a subform called sbfOrderDetails, which in its Form Footer has a text box that sums the items in the order and is called OrderDetailsTotal.

I am trying to pass that value to a text box in the main form called OrderSubtotal.

I have three questions:

1) What is the proper syntax to use to get the value of the subform control into the OrderSubtotal control on the main form? I have tried various permutations and continue to get a #Name? error.

2) If you look at the expression in the Order Subtotal control of the Add and Manage Orders form in the original Order Management template, it looks like this:

=[Order Details Subform].Form!OrderDetailsTotal

When I try to replicate that in my database, I cannot--if I add brackets around my subform name and press Enter, Access adds brackets around everything in the expression, i.e. =[sbfOrderDetails].[Form]![OrderDetailsTotal]
(which returns a #Name? error). If I edit out the brackets I don't want and then press Enter, it puts the brackets back in. In other words, Access keeps trying to "fix" my expression by either having brackets around each item, or no brackets at all! This is really annoying; is there any way to turn it off??

3) When sbfOrderDetails is set to Single Form view, I can see the Form Footer (and the value in the OrderDetailsTotal text box as well). When it is set to Datasheet view, I cannot. Why?

Thank you very much,
lcnlit

PS>I cannot attach my database since I am a new poster, and the forum is disabling the URL of the Microsoft template as well.