sum calculation

[Guest]

Hi I have a form created where I enter 3 separate amount of currencies, but
I need these 3 fields added to toal one field, and that total field needs to
print on a letter automatically that I have created under report. i have
figured out how to sum the 3 fields together but it totals them up on each
letter and I need each letter to have a different total per the information i
put in each form

hope this makes sense

 

[Guest]

To Sum 3 fields I assume you tried

=[Field1]+[Field2]+[Field3]

This formula need to be located in the CountrolSource of the text box.

But what do you mean by "totals them up on each letter"?
Can you give an example?