Syntax to invoke form.check_box for elements of a hash

I have a model which contains a hash of boolean items, like this:

@role_flags={“Owner”=>0, “Administrator”=>0, “User”=>0, “Teacher”=>0,
“HoD”=>0, “Timetabler”=>0}

I would like to use form.check_box to generate check_box fields for
each item but I can’t work out the way to pass the individual entries
in the hash to form.check_box - neither the Pragmatic book nor the
Rails on-line documentation seems to cover it.

I’m pretty new to Ruby so please excuse me if this is a very stupid
question, but can someone give me a pointer please?