Create cookie in c#

Here simple code for createing cookie and value show on button click..!!

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class _Default : System.Web.UI.Page
{
    HttpCookie mycookie = new HttpCookie("malvik");
    protected void Page_Load(object sender, EventArgs e)
    {
        if (Request.Cookies["malvik"] != null)
        {
         
            Response.Write(Request.Cookies["malvik"].Value);
        }
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        mycookie.Value = TextBox1.Text;
        mycookie.Expires = DateTime.Now.AddMinutes(1);
        Response.Cookies.Add(mycookie);
   
    }
    protected void btn1_Click(object sender, EventArgs e)
    {
        Page.Theme = "Theme1";
    }
}