title: retURL in URLFOR not redirecting correctly
body: <p>I have a VF page that is embedded inline on a custom object page layout section.  In the VF page, I used a command button to redirect to another custom object using the URLFOR New Action.</p>
  
  <pre><code>&lt;apex:commandButton onclick="window.parent.location.replace('{!URLFOR($Action.Design__c.New)}');" value="Add Design" rendered="{!IF(designId == null, true, false)}" /&gt;
  </code></pre>
  
  <p>This works and opens the custom object in the create 'New' record mode.  However, if I click 'Cancel' the retURL opens my VF page directly and not inline on the custom object page layout, which is very bad.  I displays the VF page with no way to get back to the Salesforce UI without hitting the back button.</p>
  
  <p>How can I set the retURL probably in the URLFOR method so when the user clicks cancel that it will redirect them back to the correct page?</p>