how to make 1 as 01 by entering /

hi,

in my text box have to do date validations.am done with that. Now if i enter 1/ in that textbox it should return 01 in day place same as in month and year should be like if 15 means 2015.

Source Code::

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Dat n Txtbox.aspx.cs" Inherits="Validators.Validators_Task.Dat_n_Txtbox" %>

Custom Validator

Code Behind::

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Globalization;

namespace Validators.Validators_Task

{

public partial class Dat_n_Txtbox : System.Web.UI.Page

{

protected void Page_Load(object sender, EventArgs e)

{

}

protected void CustomValidator1_ServerValidate(object sender, ServerValidateEventArgs e)

{

DateTime d;

e.IsValid = DateTime.TryParseExact(e.Value, "dd/MM/yyyy", CultureInfo.InvariantCulture, DateTimeStyles.None, out d);

}