Write below query:-
HttpCookie UsrDet = new HttpCookie();
//Add the values into cookie
UsrDet["Name"] = "John";
UsrDet["Desig"] = "Project Manager";
UsrDet["Age"] = "30";
UsrDet["Sal"] = "0.0";
UsrDet["Place"] = "UK";
//Set the cookie expire details
UsrDet.Expires = DateTime.Now.AddDays(30);
//Add to the collection
Response.Cookies.Add(UsrDet);