javascript dropdown date validation

Hi,

i have a grt hour on last day.my client don't need any date picker then second option of my is a drop-down.he accept that but validation showed be done on client side!!!!.
problem to face are :

1.Make sure the month selected has only 30 days

2. vice-verse also 31 days

3. Feb had only 28 day's

4. check year is leap year if so 29 day's.
Then i plan and create a JavaScript that validate date as per criteria 

Demo

anyway here is the javascript

    <script type="text/javascript">

        function chkDate(d, m, y) {

            var td = 0;

            if (m == 1 || m == 3 || m == 5 || m == 7 || m == 8 || m == 10 || m == 12)

                td = 31;

            else if (m == 4 || m == 6 || m == 9 || m == 11)

                td = 30;

            else {

                if (((y % 4 == 0) && (y % 100 != 0)) || (y % 400 == 0)) td = 29;

                else td = 28;

            }

            if (td >= d) return true;

            else return false;

        }

        function validate() {

          //  debugger;

            if (chkDate(document.getElementById('dd').value, document.getElementById('mm').value, document.getElementById('yy').value) == false) {

                alert("Invalid Date");

                return false;

            }

            else {

                alert("Valid Date");

            }

        }

      

    </script>

Download sample here

stay tune....

Have a nice day... 'N happy Coding :)