title: Check box :checked by condition
body: <p>I have a check box  and I want the checkbox to be checked if a parameter equals 1.  So I need the :checked to only be true if the condition is true.  </p>
  
  <pre><code>&lt;%= check_box_tag 'catalog_image', 1, :onclick =&gt; 'this.form.submit()', :checked =&gt; (params[:catalog_image] == 1)%&gt;
  </code></pre>
  
  <p>The current condition I am testing does not work.  The param will automatically be added, or subtracted, when the form submits because it is linked back to the same page.</p>