"Build" in Control Source greyed out

[briank]

I would like to created a simple calculation in my footer's text box but I
suspect that I'm missing an obvious roadblock somewhere. First of all, the
Build button in the Control Source is greyed out so I typed the calc in
manually <the calculation is =sum((val([textbox1]) + val([textbox2])) >.
When I run the report from a VBA induced Run button, the report never shows
up (keep in mind that this only happens when I add this calc field).
Probably important to note that the source query is a stored procedure.
Barring looking through endless lines of code behind the Run button, is there
an obvious solution here? TY.

 

[Marshall Barton]

I would like to created a simple calculation in my footer's text box but I
suspect that I'm missing an obvious roadblock somewhere. First of all, the
Build button in the Control Source is greyed out so I typed the calc in
manually <the calculation is =sum((val([textbox1]) + val([textbox2])) >.
When I run the report from a VBA induced Run button, the report never shows
up (keep in mind that this only happens when I add this calc field).
Probably important to note that the source query is a stored procedure.
Barring looking through endless lines of code behind the Run button, is there
an obvious solution here?

You can only use an aggregate function on record source
fields. These functions are totally unaware of controls on
a form or report.

If you can figure out where textbox 1 and 2 get their
values, then you can use those fields or expressions in the
Sum function. E.g. If you have a text box named Amount
that has an expression like =Quantity * Price, you can NOT
use =Sum(Amount) Instead you need to use:
=Sum(Quantity * Price