title: how to have select_tag in form_form
body: <p>usually in <code>form_for</code></p>
  
  <p>I do <code>p.text_field :my_colum_name</code></p>
  
  <p>but what if I have a select tag?</p>
  
  <p>I tried following but did not work</p>
  
  <pre><code>&lt;%=p.select_tag :conditions,options_for_select([ "a", "b", "c" ], "a") %&gt;
  </code></pre>
  
  <p>it says select_tag is an undefined method</p>