title: Why is select tag in rails form not working?
body: <p>I have a user registration form:</p>
  
  <pre><code>&lt;%= form_for(resource, :as =&gt; resource_name, 
          :url =&gt; registration_path(resource_name), 
          :id =&gt; "employer-form") do |f| %&gt;
      &lt;%= devise_error_messages! %&gt;
  
      &lt;p&gt;&lt;%= f.email_field :email, :autofocus =&gt; true, :title =&gt; "Enter email", :value =&gt;"Enter Email", :class =&gt;"field" %&gt;&lt;/p&gt;
  
      &lt;p&gt;&lt;%= f.text_field :profile_name, :autofocus =&gt; true, :title =&gt; "Enter Username", :value =&gt; "Enter Username", :class =&gt;"field" %&gt;&lt;/p&gt;
  
  
      &lt;p class="clearfix"&gt;
         &lt;%= f.password_field :password, :title =&gt; "Enter Password", :value =&gt; "Enter Password", :class =&gt; "field field-half" %&gt;
         &lt;%= f.password_field :password_confirmation, :title =&gt; "Retype Password", :value =&gt; "Retype Password", :class =&gt; "field field-half" %&gt;     
      &lt;/p&gt;
  
      &lt;p class="clearfix"&gt; 
         &lt;%= f.text_field :first_name, :title =&gt; "Enter First Name", :value =&gt; "Enter First Name", :class =&gt; "field field-half" %&gt;
         &lt;%= f.text_field :last_name, :title =&gt; "Retype Last Name", :value =&gt; "Enter Last Name", :class =&gt; "field field-half" %&gt;
      &lt;/p&gt;
  
      &lt;p class="clearfix"&gt;
         &lt;div class="custom-select"&gt;
             &lt;%= f.select_tag(:how_did_you_hear, options_for_select
                 ([["Bing", :bing],["College Rep", :college_rep],
                 ["Facebook", :facebook],["Google", :google],
                 ["Pinterest", :pinterest],["Yahoo", :yahoo],
                 ["Twitter", :twitter],["Other", :other]])) %&gt;
         &lt;/div&gt;  
      &lt;/p&gt;
  
      &lt;div&gt;&lt;%= f.submit "Sign up" %&gt;&lt;/div&gt;
   &lt;% end %&gt;
  </code></pre>
  
  <p>The select tag works if I take away the "f." right before it.  But if I take that away, it won't go to the user object.  If I put the "f." in, it says: </p>
  
  <pre><code>undefined method `select_tag' for #&lt;ActionView::Helpers::FormBuilder:0x007f950db434e0&gt;
  </code></pre>
  
  <p>I've seen some stackoverflow questions that are similar but don't help.  The documentation mentions this briefly but it is too complicated for a newbie like myself to understand.</p>