How to display output in xml format using wcf webservice

namespace EmployeeService
{
    [ServiceContract]
    public interface IEmployees
    {
        [OperationContract]
        List<employee> GetAllEmpDetails();

        [OperationContract]
        [WebInvoke(Method = "GET",
          RequestFormat = WebMessageFormat.Xml,
          ResponseFormat = WebMessageFormat.Xml,
          BodyStyle = WebMessageBodyStyle.Wrapped,
          UriTemplate = "Employee/{id}")]
        
        List<employee> GetEmpDetailsbyId(string id);

    }

    [DataContract]
    public class Employee
    {
        [DataMember]
        public string EmpID { get; set; }
        [DataMember]
        public string EmpName { get; set; }
        [DataMember]
        public string Department { get; set; }
        [DataMember]
        public string Designation { get; set; }

    }
}