Include jQuery
<script src="http://code.jquery.com/jquery-1.10.1.min.js"></script>
<script>
// Then use an event handler to check when the select changes
$('select').on('change', function()
{
// Show an alert
alert( "The new value of the select is " + $(this).val() );
// You should place your logic here to do what you want with that value
// E.g. change the page
document.location.href = $(this).val();
});
</script>