In Tally, Button or Key have a property called "Inactive". Make this as Yes to inactive a Button.
Ex: Inactive Delete Delete Button
[#Key : Form Delete]
Inactive : Yes
;;Delete object in daybook
[#Key: BottomToolBarBtn3]
Inactive: Yes
Ex: Inactive Delete Delete Button
[#Key : Form Delete]
Inactive : Yes
;;Delete object in daybook
[#Key: BottomToolBarBtn3]
Inactive: Yes