title: cakePHP: how set error validation to input field manually in controller
body: <p>I want  set error validation to input field manually in controller
  example:</p>
  
  <pre><code>  if ($remainTime &lt; 30) {
        ..... set error validation in here (error: limitTime ), ( error is not in model )
    }
  </code></pre>
  
  <p><strong>other question</strong>: i want to ask :
  bindModel ( in this case , I use bindModel in Behaviors ) 'll cause loss of relationship with other model 
  but is bindModel cause loss of $var validate,too ?</p>