/ Id-Extras Forum / subtraction of two fields / Reply To: subtraction of two fields

#6382
Ariel
Participant

Hi Jennifer,

Even Acrobat itself doesn’t offer a simple way to do subtractions. Not quite sure why, but probably because x – y (and x / y) is not the same as y – x and y / x (as opposed to addition and multiplication, which are commutable).

So a custom calculation script is needed to handle this.

The basic idea is as I mention in this thread: http://id-extras.com/forum/viewtopic.php?id=53

In your case, we would need to modify it a little, like this:

To get the value of a field, use this command:

Code:
this.getField(“Field1”).value

To update the value of the selected field, use:

Code:
event.value = …

So putting it all together, try the following as your custom calculation script:

Code:
event.value = this.getField(“Field1”).value – this.getField(“Field2”).value

Does that work?
Ariel