The focus method in jQuery doesn't work
<p>The following code is intended to check if 4 numbers are entered in the blurred field. If not, the field value is deleted, and the field is focused. The deletion works fine, but the the call to focus() does not work.</p>

<pre><code>$('input.dateValue').live('blur',function(event){
  if (!(/(\d){4}$/.test($(this).attr('value')))) $(this).attr('value','').focus();
});
</code></pre>

<p>Why does the call to focus() not focus the field?</p>
