jquery snippet

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.5.2/jquery.min.js"></script>
<script type="text/javascript">// <![CDATA[
$(document).ready(function() {
  function filterPath(string) {
    return string
      .replace(/^\//,'')
      .replace(/(index|default).[a-zA-Z]{3,4}$/,'')
      .replace(/\/$/,'');
  }
  $('a[href*=#]').each(function() {
    if ( filterPath(location.pathname) == filterPath(this.pathname)
    && location.hostname == this.hostname
    && this.hash.replace(/#/,'') ) {
      var $targetId = $(this.hash), $targetAnchor = $('[name=' + this.hash.slice(1) +']');
      var $target = $targetId.length ? $targetId : $targetAnchor.length ? $targetAnchor : false;
       if ($target) {
         var targetOffset = $target.offset().top;
         $(this).click(function() {
           $('html, body').animate({scrollTop: targetOffset}, 2000);
           return false;
         });
      }
    }
  });
});
// ]]></script>