java.lang.NoClassDefFoundError: org.hibernate.cfg.Configuration 是什么错误？？？
<?xml   version= "1.0 "   encoding= "UTF-8 "?>  
<beans   xmlns= "http://www.springframework.org/schema/beans "
    xmlns:xsi= "http://www.w3.org/2001/XMLSchema-instance "
    xsi:schemaLocation= "http://www.springframework.org/schema/beans  
    http://www.springframework.org/schema/beans/spring-beans-2.0.xsd ">

        <bean   name= "/empLogin "   class= "EmployeeLoginAction ">
                <property   name= "empMgr "   ref= "EmployeeManagerService "/>
        </bean>

<bean   id= "EmployeeManagerService "   class= "EmployeeManagerServiceImpl ">

<property   name= "employeeDAO "   ref= "EmployeeDAO "/>

</bean>

<bean   id= "EmployeeDAO "   class= "EmployeeDAOHibernate "   lazy-init= "true ">
property   name= "employeeDAO "   ref= "EmployeeDAO "/
</bean>

<bean   id= "dataSource "
                    class= "org.springframework.jdbc.datasource.DriverManagerDataSource ">  
                <property   name= "driverClassName "  
                                    value= "oracle.jdbc.driver.OracleDriver "/>
                <property   name= "url "
                                    value= "jdbc:oracle:thin:@localhost:1521:sammi "/>  
                <property   name= "username "   value= "system "/>  
                <property   name= "password "   value= "sammi "/>  
        </bean>

<bean   id= "sessionFactory "    
    class= "org.springframework.orm.hibernate3.LocalSessionFactoryBean "          
    destroy-method= "close ">  
 
    <property   name= "configLocation ">
  <value> hibernate.cfg.xml </value>
    </property>

                <property   name= "dataSource "   ref= "dataSource "/>  
                <property   name= "mappingResources ">  
                        <list>  
                                <value> Employee.hbm.xml </value>  
                        </list>  
                </property>