jquery error: val() is not a function
<p>Why I'm getting this error? <code>val is not a function</code> when I validate the number.</p>

<pre><code>$(this).find('#register-validation .next').click(function() {
     var _parent = $(this).parents('#register-validation');
     $('.loading-big').html(loadMsg).fadeIn(300);
     _parent.find('input.required').each(function(index) {
         if($(this).val() == "" || $(this).val() == errReq) { // here is fine
             $(this).val(errReq);
             $(this).addClass("error");
         }
         else if(isNaN($(this).hasClass('number').val())) { // but when validation goes here, I got this error.
             $(this).val(errNum);
             $(this).addClass("error");
         }
         else {
             $(this).removeClass("error");
         }
     });
});
</code></pre>

<p>Please help. Thanks a lot.</p>
