title: Rails form_for radio_button "Can't be blank"
body: <p>I have the following code:</p>
  
  <pre><code>&lt;% form_for(@libation) do |f| %&gt;
    &lt;%= f.radio_button :carbonated, true  %&gt; &lt;%= f.label :carbonated, "Yes" %&gt;
    &lt;%= f.radio_button :carbonated, false %&gt; &lt;%= f.label :carbonated,  "No" %&gt;
  &lt;% end %&gt;
  </code></pre>
  
  <p>The <code>carbonated</code> column in the database is of type <code>tinyint</code>.<br>
  And when the above is run and I click <code>No</code> I get a big red box telling me:</p>
  
  <pre><code>1 error prohibited this libation from being saved
    There were problems with the following fields:
    * Carbonated can't be blank
  </code></pre>
  
  <p>Any ideas?<br>
  -thanx</p>