JQuery Ui Effects not working

Question

When I use hide() or show() they work - but When I use effect(), they don't, here is a little peace of code:

  <link href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/base/jquery-ui.css" rel="stylesheet" type="text/css"/>
  <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.5/jquery.min.js"></script>
  <script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/jquery-ui.min.js"></script>

and my Script is:

<script type="text/javascript">
$(document).ready(function() {
    $(".palas").fadeIn(2000);
     /*$(".palas").click(function () {
          $(this).hide( "fold", 
                  {horizFirst: true }, 2000 );
    });*/
$(".palas").click(function () {
          $(this).hide();
    });
});
</script>

Uncommented part is working well, the commented part is not, I Even tried more options that this.

Answer 1

change you jquery ui link from version 1.5 to version 1.8

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8/jquery.min.js"></script>