Calculations On Main Form Do Not Reflect Calculations On Subform

I have solved the problems getting values on the subform. I have not in getting values on the subform.For instance, on the one titled phone use the formula in the tutorial is:

=[sbfCustomerRoomUse].[Form]![txtTotalPhoneUse]

#Error results when the doc is put into a form mode.

Now when I input each value in the equation above separately.I still get no entry.

For " = sbfCustomerRoomUse" , I get #Error;
and for "= txtTotalPhoneUse", I get #Name.

CustomerRoomUse and txtTotalPhoneuse are from the subform that was dropped into the customer form in a previous step. It shows that explicitly when designed sbfCustomerRoomUse on the main that CustomerRoomUse come from a subform. This does not seem to need to be done with txtTotalPhoneuse, and I am not sure why. Neither one gives me a desired calculation result.