web service return old values every time asp.net

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.Text;
using System.Data;

namespace WcfService1
{
// NOTE: If you change the class name "Service1" here, you must also update the reference to "Service1" in Web.config and in the associated .svc file.
public class Service1 : IService1
{
public string GetData(int value)
{
return DateTime.Now.ToString();
}


}
}