Capturing Rails 3 Multiselect Input Params

Question

I have a multiselect form control (fig. 1). When I select more than 1 value, Firefox sends both values (fig. 2). But only the last value gets sent as a input value to my controller (fig. 3). How do I get all those values passed on to my controller?

  <form action="html_items/search" method="post" >

    <!-- Criteria --> 
    <div style="float:none;">
      <label>Content Provider </label>
      <select multiple id="content_provider" name="content_provider">
        <option value="FLR">Flare</option>
        <option value="SLDT">Slashdot</option>
      </select>
    </div>

    <input type="submit" value="Search" />

  </form>

fig. 1

Parametersapplication/x-www-form-urlencoded
content_provider FLR
content_provider SLDT
fig. 2

PARAMs[{"content_provider"=>"SLDT", "controller"=>"html_items", "action"=>"search"}]
...
fig. 3

Thanks
Tim