Updating the checkboxes with data from the db

I'm making a musicians site where the users are able to check some
checkboxes with their music-style if they want to edit their music-style
i would like the previous checked checkboxes to be checked.

here's some code

<div class="form_row">
        <label for="looking_for"><%= label %>:</label>
<table>
<tr>
<% @i = 0 %>
<% @status = false%>
    <% collection.each do |db_field| %>
      <% db_collection.split(", ").each do |collection_field| %>
        <% if db_field == collection_field %>
          <% @status = true %>
          <% else %>
            <% @status = false%>
          <% end %>
        <% end %>
      <td>
       <%= check_box_tag array, db_field, @status %>
       <%= db_field %>
      </td>
       <% if @i == 1 %>
       <% @i = -1 %>
       </tr><tr>
       <% end %>
       <% @i = @i +1 %>
       <% end %>
</tr>
</table>
</div>

collection could be:

VALID_STYLES = ["Blues", "Country", "Elektronisk", "Folkemusik",
"Hip-Hop",
                  "Jazz", "Klassisk", "Metal", "Pop", "R&B og Soul",
"Rock",
                  "Verdensmusik"]

and the db_collection could be:

Blues, Elektronisk, R&B og Soul

I don't know why, but with the code i have now R&B og Soul would get
updated in the view so that the checkbox would be checked, it's always
the last option that gets checked.