Jquery Was loaded on page postback

Scenario :
   Jquery was not loading when the page is partially loaded.(update panel).
  Script used :
    <script type="text/javascript">
        $(window).load(function () {
            $('#nivo-slider').nivoSlider();
        });
    </script>
  Solution : (use pageLoad instead of $...)
     <script type="text/javascript">
        function pageLoad()
          {
             $('#nivo-slider').nivoSlider();
         }
    </script>