title: Rails f.check_box set checked/unchecked values
body: <p>so I got a form helper in rails with a checkbox;
  I want that checkbox to have values as "thatvalue" or "thisvalue" when checked or unchecked;
  I haven't found anywhere how to set this up with </p>
  
  <pre><code>f.check_box :field
  </code></pre>
  
  <p>I found something like that</p>
  
  <pre><code>&lt;%= form.check_box :field, {}, "thisvalue", "thatvalue"  %&gt;
  </code></pre>
  
  <p>but it doesn't work, because I also set :class and :style inside my tag, so having something like</p>
  
  <pre><code>&lt;%= form.check_box :field, {}, "thisvalue", "thatvalue", :class =&gt; "checkbox", :style =&gt; "display:none;" %&gt;
  </code></pre>
  
  <p>errors and tells me wrong number of arguments (5 for 4)</p>
  
  <p>so right now I have to "hack" it in my controller, and set my field depending on if my checkbox is 0 or 1... which is pretty bad.</p>
  
  <p>any idea?</p>