buttons for a drop down list

The "show" for a row from feeds works correctly, showing both rows which that feed row. However, I'd like to add a "add" button (and a "remove"?) to the "Editing feed" page so that the the rows from categories will be associated/unassociated with that feeds row.

(There's a many-to-many relationship between "feeds" and "categories".)

Feed: feed1 Edit | Back Itemized Categories cat1 category2

<http://localhost:3000/feeds/show/1&gt;

Feed: feed2 Edit | Back

<http://localhost:3000/feeds/show/2&gt;

Editing feed

Feed

Category Show | Back

<http://localhost:3000/feeds/edit/1&gt;

thufir@arrakis ~/Desktop/strawr $ thufir@arrakis ~/Desktop/strawr $ tail app/views/feeds/show.rhtml -- lines=13

<% if @feed.has_categories? %>   <h3>Itemized Categories</h3>   <table>   <% for category in @feed.categories %>     <tr>       <td><%= category.category %></td>     </tr>   <% end %>   </table> <% end %>

thufir@arrakis ~/Desktop/strawr $ thufir@arrakis ~/Desktop/strawr $ tail app/views/feeds/_form.rhtml -- lines=2

<p><label for="category_id">Category</label><br/><%= select("post", "category_id", Category.find_all.collect {|c| [c.category, c.id]}) %></p> thufir@arrakis ~/Desktop/strawr $

thanks,

Thufir