You will probably get more responses if you move this to Discussions, rather than in the K-12 area.
Also, please post screen shots of your script. You may be trying to type something that is not a field (missing context of the table occurrence, perhaps?) Have you tried selecting the field from the list?
FM Version information would be helpful as well.
Thanks for the quick response. Will move discussion (new to this as you can see!) and also put up screenshot.
Im using latest version 14.