I want to sum all Invoice Amounts but thave them in sepreated periods, so I ahve totals for 1 to 12 periods.  

 

From there I intend to put actual budget against Invoiced and then take the 2 away from each other.

 

How do I create the formula, I have tried several syntax but with no luck.

Also is there a way to add 12 fields that can be used to store this years budget amounts (no databse field avaialble presently), I tried a text box but this did not work.

Thanks

 

I tried the code you described but it does not work