Pas de persister pour la classe d'Erreur

quand je lance l'application j'ai "Pas de persister pour le Test.Étudiants" Erreur
Je suis nouveau dans Nhibernate Cartographie ,je ne peux pas comprendre cela

Comment puis-je le résoudre ?? plz help

NHibernate Configuration de la partie

App.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
 <configSections>
  <section name="hibernate-configuration"
    type="NHibernate.Cfg.ConfigurationSectionHandler, NHibernate" />
</configSections>
<hibernate-configuration xmlns="urn:nhibernate-configuration-2.2">
<session-factory>
  <property name="connection.provider">
    NHibernate.Connection.DriverConnectionProvider
  </property>
  <property name="connection.driver_class">
    NHibernate.Driver.SqlClientDriver
  </property>
  <property name="connection.connection_string">
    Server=(local);database=Student;Integrated Security=SSPI;
  </property>
  <property name="dialect">
    NHibernate.Dialect.MsSql2005Dialect
  </property>
  <!--<property name="proxyfactory.factory_class">
    NHibernate.Bytecode.DefaultProxyFactoryFactory, NHibernates
  </property>-->
  <property name="show_sql">
    false
  </property>
</session-factory>

Le Programme Principal

programme.cs

  using System;
  using System.Collections.Generic;
  using System.Linq;
  using System.Text;
  using NHibernate;
  using NHibernate.Cfg;
 namespace Test
  {
   class Program
    {
      static void Main(string[] args)
       {           
        ISessionFactory factor = new Configuration().Configure().BuildSessionFactory();
        if(factor!=null){
            Console.WriteLine("Configured");
        }
        else{
            Console.WriteLine("Not Configured");
        }
        Student std = new Student { Fname = "James", Lname = "Bond", Address = "32 Baker Street", Institution = "MIT" };
        using (ISession session = factor.OpenSession()) 
        {
            using (ITransaction transaction= session.BeginTransaction())
            {
                try 
                { 
                session.Save(std);
                transaction.Commit();
                session.Close();

                }
                catch(Exception e)
                {
                    Console.WriteLine("ERROR :" + e);
                }
            }           
        }               
    }
    //protected ISessionFactory factory;


    protected void execute_query()
    {

    }
}

}

Partie de la cartographie

Student.hbm.xml

  <?xml version="1.0" encoding="utf-8" ?>
      <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" auto-import="true">
      <class name="Test.Student" table="Info" lazy="true">
     <id name="Id" type="int" column="Id">
       <generator class="native" />
    </id>

       <property name="Fname" column ="Fname"/>
<property name="Lname" column="Lname"/>
<property name="Address" column="Address"/>
<property name="Institution" column="Institution"/>

<!-- We don't have to specify a column name if its the same 
     as the variable name -->