Horizontal Scrolling of page not working correctly

Horizontal Scrolling of page not working correctly

Can anyone help, I cant  see why this code will not scroll to section 4 and when it does it goes to section 1. have checked the link and they seem to be working.
 
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" " http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
    <head>
        <title>Website Horizontal Scrolling with jQuery</title>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
        <meta name="description" content="Website Horizontal Scrolling with jQuery" />
        <meta name="keywords" content="jquery, horizontal, scrolling, scroll, smooth"/>
        <link rel="stylesheet" href="css/style.css" type="text/css" media="screen"/>
    </head>
    <style>
        a{
            color:#fff;
            text-decoration:none;
        }
        a:hover{
            text-decoration:underline;
        }
        span.reference{
            position:fixed;
            left:10px;
            bottom:10px;
            font-size:13px;
            font-weight:bold;
        }
        span.reference a{
            color:#fff;
            text-shadow:1px 1px 1px #000; /*  to blurry sort this later */
            padding-right:20px;
        }
        span.reference a:hover{
            color:#ddd;
            text-decoration:none;
        }































    </style>
    <body>
      

        <div class="section black" id="section1">
            <h2>Section 1</h2>
            <p>
                MY Spectre around me night and day
                Like a wild beast guards my way;
                My Emanation far within
                Weeps incessantly for my sin.
            </p>
            <ul class="nav">
                <li>1</li>
                <li><a href="#section2">2</a></li>
                <li><a href="#section3">3</a></li>
                <li><a href="#section4">4</a></li>
            </ul>
        </div>
        <div class="section white" id="section2">
            <h2>Section 2</h2>
            <p>
                ‘A fathomless and boundless deep,
                There we wander, there we weep;
                On the hungry craving wind
                My Spectre follows thee behind.




















            </p>
            <ul class="nav">
                <li><a href="#section1">1</a></li>
                <li>2</li>
                <li><a href="#section3">3</a></li>
                <li><a href="#section4">4</a></li>
            </ul>
        </div>
        <div class="section black" id="section3">
            <h2>Section 3</h2>
            <p>
                ‘He scents thy footsteps in the snow
                Wheresoever thou dost go,
                Thro’ the wintry hail and rain.
                When wilt thou return again?













            </p>
            <ul class="nav">
                <li><a href="#section1">1</a></li>
                <li><a href="#section2">2</a></li>
                <li>3</li>
                <li><a href="#section4">4</a></li>
            </ul>
        </div>
       
         <div class="section black" id="section4">
            <h2>Section 4</h2>
            <p>
                ‘He who drinks
                too much 'old specklen hen',
                will rule the rust.













            </p>
            <ul class="nav">
                <li><a href="#section1">1</a></li>
                <li><a href="#section2">2</a></li>
                <li><a href="#section3">3</a></li>
                <li>4</li>
            </ul>
        </div>






        <!-- The JavaScript -->
        <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>  
        <script type="text/javascript" src="jquery.easing.1.3.js"></script>
        <script type="text/javascript">
            $(function() {
                $('ul.nav a').bind('click',function(event){
                    var $anchor = $(this);
                    /*
                    if you want to use one of the easing effects:
                    $('html, body').stop().animate({
                        scrollLeft: $($anchor.attr('href')).offset().left
                    }, 1500,'easeInOutExpo');
                     */
                    $('html, body').stop().animate({
                        scrollLeft: $($anchor.attr('href')).offset().left
                    }, 1000);
                    event.preventDefault();
                });
            });
        </script>
    </body>
</html>