How do I make easy scrolling with jquery?

Hello!

I am new to javascript but, I am trying to add jquery easing plug-in to my site.
The problem that I am having is that it is not working for me.
I am not sure if it is in the function itself or in how I am calling the javascript.
Any help would be greatly appreciated.
Thank you.

Here is the code that I have in the head of the page:

<!--jquery easing-->
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
<script type="text/javascript" src="js/jquery.easing.1.3.2.js"></script>

<!--lightbox-->
<script type="text/javascript" src="js/prototype.js"></script>
<script type="text/javascript" src="js/scriptaculous.js?load=effects,builder"></script>
<script type="text/javascript" src="js/lightbox.js"></script>






<script>
$(function() {
// catch all clicks on a tag
$("a").click(function() {
// check if has hash
if(this.hash) {
// get rid og # sign
var hash = this.hash.substr(1);
// get the position of <a name>
var $toElement = $("a[name="+hash+"]");
var toPosition = $toElement.position().top;
// scroll/animate to that element
$("body,html").animate({
scrollTop : toPosition
},2000,"easeOutExpo");
// don't do the jump
return false;
}
});
if(location.hash) {
var hash = location.hash;
window.scroll(0,0);
$("a[href="+hash+"]").click();
}
});

</script>