title: UIKeyboard with iPhone OS 4
body: <p>Hi I have a big problem with iPhone 4.0 OS with this code</p>
  
  <pre><code>if([[keyboard description] hasPrefix:@"&lt;UIKeyboard"] == YES) {
  }
  </code></pre>
  
  <p>in condition UIKeyboard it not working. I try "UILayoutContainerView"
  but it not working too.</p>
  
  <p>please.</p>