I am looking for a code in javascript that ensures future da

    <script type="text/javascript">

            function SelectDate(e) {

                var PresentDay = new Date();

                var dateOfBirth = e.get_selectedDate();

                var months = (PresentDay.getMonth() - dateOfBirth.getMonth() +
 (12 * (PresentDay.getFullYear() - dateOfBirth.getFullYear())));

                document.getElementById("txtCONSULTANT_AGE").value = Math.round(months / 12);

                document.getElementById("txtCONSULTANT_AGE").readOnly = true;

                if (dateOfBirth > PresentDay) {

                    alert("error");

                    document.getElementById("txtCONSULTANT_AGE").value = "You are Going to Born";

                }

            }         

    script>