title: Magento - Custom Order Fields - Tutorial Error?
body: <p>I'm following the tutorial located at: </p>
  
  <p><a href="http://www.magentocommerce.com/wiki/5_-_modules_and_development/how_to_add_custom_field_in_billing_and_shipping_address_in_frontend_and_backend" rel="nofollow">http://www.magentocommerce.com/wiki/5_-_modules_and_development/how_to_add_custom_field_in_billing_and_shipping_address_in_frontend_and_backend</a></p>
  
  <p>There's no mention of which version this is for, but it's less than a year old, so I don't see why it shouldn't work on 1.6.2 (the sandbox I'm testing it in - fresh install, nothing done other than change package/theme). </p>
  
  <p>However, after getting this together, the billing address block is failing during checkout (as well as other areas where this should be visible) and the log states:</p>
  
  <pre><code>2012-01-31T20:46:01+00:00 ERR (3): Warning: led to open stream: No such file or directory  in /var/www/order-add-field/lib/Varien/Autoload.php on line 93
  2012-01-31T20:46:01+00:00 ERR (3): Warning: include(): Failed opening 'Mage/Eav/Model/Attribute/Data/.php' for inclusion (include_path='/var/www/order-add-field/app/code/local:/var/www/order-add-field/app/code/community:/var/www/order-add-field/app/code/core:/var/www/order-add-field/lib:.:/usr/share/php:/usr/share/pear')  in /var/www/order-add-field/lib/Varien/Autoload.php on line 93
  </code></pre>
  
  <p>So I'm led to believe there is something wrong with how the model is set up. Per the tutorial, config.xml includes (inside global tag):</p>
  
  <pre><code>&lt;models&gt;
      &lt;orderfields&gt;
          &lt;class&gt;Ps_Orderfields_Model&lt;/class&gt;             
      &lt;/orderfields&gt;      
  &lt;/models&gt;
  </code></pre>
  
  <p>The tutorial doesn't state any models needing to be set up, yet it appears as though something is missing. Do I need the Model file? The mysql install script I assumed would handle this... It feels just a step away, but I'm not sure what. </p>