title: using :reject_if to check for empty field
body: <p>In Rails 2.3.5 model I am using </p>
  
  <pre><code>accepts_nested_attributes_for :questions, :reject_if =&gt; lambda { |a| a[:content].blank? }
  </code></pre>
  
  <p>But its rejecting if there is the textbox is not empty..
  How can I make it to reject only if there is nothing entered into the textbox ?</p>