Format Date as MMM dd yyyy in JavaScript

<script type="text/javascript">
    window.onload = function () {
        alert(SetDateFromat('2014-12-11T00:00:00'));
    }

    function SetDateFromat(datetime) {
        var fullDate = new Date(datetime);
        var month = fullDate.toLocaleString('en-US', { month: 'short' });
        var date = fullDate.getDate();
        return month + " " + date + "," + fullDate.getFullYear();
    }
</script>