Did you include this script:
<script language="JavaScript" type="text/javascript">
$(document).ready(function(){
$('.carousel').carousel({
interval: 2000
})
});
</script>
And even it its not working, please check whether you are calling the above script before calling the jquery. So, it should be like this:
<!-- Calling jquery first -->
<script language="JavaScript" type="text/javascript" src="scripts/jquery.js"></script>
<script language="JavaScript" type="text/javascript" src="scripts/bootstrap.min.js"></script>
<!-- Carousel -->
<script language="JavaScript" type="text/javascript">
$(document).ready(function(){
$('.carousel').carousel({
interval: 3000
})
});
</script>
