search for: doing_checkbox_adds_with_habtm

I''m 100% positive this has come up multiple times before. I just can''t find it for some reason. I''ve got a HABTM relationship, we''ll just say Item HABTM categories. When I edit an Item via a form, I''d like there to be check boxes for all the categories, and they''ll obviously be checked if an Item has a relationship with a particular