How would I do this?

if field c is "Yes"

then transfer value of field a to field b

if field c is "No"

then transfer value of field b to field a

any help is greatly appreciated

A simple way would be:

If(C="Yes")

Set Variable ($D;Value:$D=:

Set Field(B;A)

Set Field(A;$D)

End If

And the reverse for "No"

What would be "the reverse" here?

OK, 'comment', maybe the word "reverse" was not the right choice, but in helping a beginning I will gladly post the alternative answer choice so no thinking is necessary.

If(C="No")

Set Variable ($D;Value:$D=A)

Set Field(A;:

Set Field(B;$D)

End If

Doesn't this "reverse" process accomplish the same result? What is the reverse of "swap"?

The script steps I posted, I believe, answer the original question, although it seems like I am missing something.

Please explain.

The original question is not clear to me. If I read it literally, it says:

If [ C = "Yes" ]

Set Field [ B ; A ]

Else

Set Field [ A ; B ]

End If

But the title of the thread says "swap". A swap is what both your scripts do - and they both do the same thing, except in different order. So the value of C is simply ignored.

You're right. Only one swap is needed. If C="No" then it should do nothing.

Although in your example, doesn't the result of C="Yes" leave the values for A and B both equal to A, and the original value of B is lost. Thus it is not a "swap" but maybe just a replacement of value.

Yes, my script does literally what the original post says should be done, therefore one of the two values is lost in the process.

I suspect the real answer here lies in a calculation field =

Case ( C = "Yes ; A : B )

but as I said, I do not really understand the question.