Table A (Page A) has a Boolean field of Mail (Default = false) and that field is set to Editable = False.
Table B (Page B) has also a Boolean field of Mail (Default = false) and that field is set to Editable = True.
Table C with Page C that is the Main page of the forms to takes Page A and B as a part of Subpagelink.
Now I want to set Mail Field (Table A) - Editable = True,
WHEN I change Mail Field (Table B) ---> Boolean = True by ticking the boxed in the web client.
How can I code?