public static void SetClientInformation(ClientInformation ci)
 {
     System.Web.HttpContext.Current.Session[_SessionKey] = ci;
 }
 public static ClientInformation GetClientInformation()
 {
     ClientInformation ci= (ClientInformation)System.Web.HttpContext.Current.Session[_SessionKey];
     if (ci == null) ci = new ClientInformation();
     return ci;
 }