title: Form_for select field, concatenating data into the display string
body: <p>I am trying to use a <code>form_for</code> <code>collection_select</code> to display some select field options of account types.</p>
  
  <p>Its occurred to me that it would be easier for the user if they could see the price of the type in each select option</p>
  
  <p>this is my currently not-working code:</p>
  
  <pre><code>&lt;%= a.collection_select :account_type, AccountType.all, :id, (:name+" - "+number_to_currency(:price)) %&gt;
  </code></pre>
  
  <p>how can i concatenate the values so that <code>(:name+" - "+number_to_currency(:price))</code> will actually work and not throw an error?</p>