Want to Update Object area field

I'm creating an Area Plan and for room tags I have created an object area field and inserted in a attribute block and upon changing or modifing the object or room size, I want area field to be updated. Is there any way to do so. And I don't know any scripting.

Thanks in advance

Try the Updatefield command

Alternatively go to Options -> User Preferences -> Field update Settings

You can get fields to update on plot, regen, open, save etc. So all you have to do is regen/save and the fields update.

Be careful having a lot of fields 150+ and having fields update on regen can be a little bit slow for some computers.