LogIn in asp.net c# By Cookie

// Create Cookie
Response.Cookies["UserName"].Value = "value Here";
Response.Cookies["AdminId"].Value = "value Here";
Response.Redirect("ToPage");

OR  Create Cookie With Expiration Time
 HttpCookie cookie_lid = new HttpCookie("lId", "value Here");
cookie_lid.Expires = DateTime.Today.AddDays(1);
Response.Cookies.Add(cookie_lid);

// To Delete Cookie

Response.Cookies["UserName"].Expires = DateTime.MinValue;
Response.Cookies["AdminId"].Expires = DateTime.MinValue;


// Check Cookie is Exsits other wise redirect default
if (Request.Cookies["UserName"] == null ||string.IsNullOrEmpty(Request.Cookies["AdminId"].Value))
            {
                Response.Redirect("Default.aspx");
            }