I need help with a really simple subtraction in livecycle, thanks you!

First, you really ought to give your fields more descriptive names.

Have you read about FormCalc? Look it up in the LiveCycle help docs. And there is a FormCalc reference and other helpful materials at:
http://kb2.adobe.com/cps/330/330467.php

FormCalc is the simple scripting language for LiveCycle forms. To use it you would enter exactly the subtraction code in your post above into the Calculate event for "undefined_30".

Thom Parker
The source for PDF Scripting Info
[url=http://www.pdfScripting.com]pdfscripting.com[/url]

The Acrobat JavaScript Reference, Use it Early and Often
[url=http://www.adobe.com/devnet/acrobat/javascript.php]http://www.adobe.com/devnet/acrobat/javascript.php[/url]

Then most important JavaScript Development tool in Acrobat
[url=http://www.acrobatusers.com/tutorials/2006/javascript_console][b]The Console Window[/b][/url]

I tried that and it's not working (formcalc - there's no subtract function in formcalc). I also tried cutting and pasting some javascript I found and modifuning it with my field names... The two cells I'm tring to subtract are also based on form cals "sum" calculations. Is that a problem? Each is an addition of several other form fields.

Thanks,
Rob

wow, that was super easy... Justn like you said i did a - b = C and it was perfect, no code really even needed. Thanks! I was trying to make it too complicated.

Best,
rob