Hi. Thanks for your previous responses.  I'm getting an error msg when I open this form in Reader and start entering info into the fields that are included in my calculation. Here's what the error  box says:Script failed (language is formcalc; content is xfa[0].form1[0].#subbform[0].WD1[0])script=Su...

It looks like we found an answer to my problem but I'm getting this error message.My syntax calculates correctly but this error meg pops up.  Can you tell me what it means?

I have a calculation (script below) where DN or DV are not always part of the sum. Trouble is both DV and DN have to be filled in to get the result.How can I script these 2 fields to where one or both are calculated?SUM=(PD1*DN*DV[WD1*CT])/BPY