Autoscroll script not works

Question

the script shown here works at link but not works when i put inside web site, what is wrong ?http://jsfiddle.net/QUCWe/

//<![CDATA[ 
$(window).load(function(){
function scroll(speed) {
    $('html, body').animate({ scrollTop: $(document).height() - $(window).height() }, speed, function() {
        $(this).animate({ scrollTop: 0 }, speed);
    });
}

speed = 1000;

scroll(speed)
setInterval(function(){scroll(speed)}, speed * 2);
});//]]>  

Answer 1

i change speed * 2 and it worked;

//<![CDATA[ 
$(window).load(function(){
function scroll(speed) {
    $('html, body').animate({ scrollTop: $(document).height() - $(window).height() }, speed, function() {
        $(this).animate({ scrollTop: 0 }, speed);
    });
}

speed = 1000;

scroll(speed)
setInterval(function(){
scroll(speed)
}, 3000);
});//]]>