Rails - Sep 2005 - check_box helper and array

Hello fellow Rails developers

I am stuck with the following problem:
I have a Project that has_many languages. All available languages are saved
in a table. I a view I want the user to select the languages the project
supports. In order to do that I iterate over all available languages using:
<% for language in Language.find(:all) %>
<%= check_box("language", language.id,
@project.has_language?(language.id) ?
{:checked => "checked"} : {}) %>
<% end %>

With Project declared like this:

class Project < ActiveRecord::Base
    has_many :languages
    
    def has_language?(id)
        for language in languages
            return true if language.id==id
        end
        false
    end
end

And language:

class Language < ActiveRecord::Base
    belongs_to :project
End


This rather standard issued I thought can be solved easier in rails.
Something like an "automatic" check if the project contains a language
from
the global list of languages.

So far this is working, but is there a more clever way to check the
languages the project contains?

Thanks in advance,
Phil