How to check something with if

I have comment and replay tables.

comment: id, user_id, comm reply: id, user_id,comm_id, reply, candy

The user will write a comment and the others will reply. After that, the user who writed the comment can give a candy to a reply. After he give the candy, i want to disable the button (dissapear) from any reply from that comment. How can i do that? what is the logic?