Formula in Lotus Approach 9.8 Form View

[burnout421]

I have created an inventory database and want to show in a 'Form' view information about qty received, qty on hand and qty moved in last month. The formula itself is simple:
Qty on hand at end of last month (A)+ Qty received this month (B)- Qty on hand at end of this month = Qty moved this month (D)
A+B-C=D A, B, C and D representing fields on the form.
My problem is that I don't want D to display anything at all if any of A or B or C are empty. Is it possible to do this and, if so , can anyone help me with the formula?
You may have guessed, I am by no means an expert!

 

[suesloan]

D = If(IsBlank(A) or IsBlank(B) or IsBlank(C),'',A + B - C)

That should do it!

Sue Sloan

 

[burnout421]

Thanks very much Sue.