Date Validation between Startdate and end date using Javascript for ajax Calendar Control

Date Validation between Startdate and end date using Javascript

  function calculate(sender, args) {

            var value1 = document.getElementById('<%=txtSDate.ClientID%>').value.split("/");

            var value2 = document.getElementById('<%=txtEDate.ClientID%>').value.split("/");

            var dttime = new Date(value1[2], value1[1] - 1, value1[0]) //Month is 0-11 in JavaScript

            today = new Date(value2[2], value2[1] - 1, value2[0])

            date1 = new Date(today)

            date1.setHours(0, 0, 0, 0);

            if (dttime > date1) {

                document.getElementById('<%=txtEDate.ClientID%>').value = "";

                alert("From date is greater than to date! ");

            }

            else {

                //Get 1 day in milliseconds

                var oneday = 1000 * 60 * 60 * 24

                //Calculate diff between the two dates, and convert to days

                document.getElementById('<%=txtNoofDays.ClientID%>').value = (today.getTime() - dttime.getTime()) / (oneday);

            }

        }


it will Calculates diff between the two dates, and convert to days