...how can we make the button inactive otherwise all or some of the filed are filed.../QUOTE]
Is that supposed to be 'all or some of the fields are filled?
Or something else?
If the former, you don't need to make the button inactive, but rather prevent the current Record from being saved (using validation in the Form_Update event) until all required Fields are populated. This will also prevent the user from closing the Form and saving an incomplete record.
Linq ;0)>