Please help me with the following error. I get the following error. I generated my baseclasses using HibernateSynchronizer.

Hibernate version: /b] 3.0

[b]Mapping documents:<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping package="com.wos.hibernate.util">
<class name="PmUser" table="pm_user">
<id
name="id"
type="java.lang.String"
column="USER_ID"
>
<generator class="assigned"/>
</id>

<property
name="userActiveStatus"
column="user_active_status"
type="java.lang.String"
not-null="false"
length="1"
/>
<property
name="userStatus"
column="USER_STATUS"
type="java.lang.Short"
not-null="false"
length="6"
/>
<property
name="userName"
column="USER_NAME"
type="java.lang.String"
not-null="true"
length="50"
/>
<property
name="licenseStatus"
column="license_status"
type="java.lang.String"
not-null="false"
length="1"
/>
<property
name="userPasswdExpDate"
column="USER_PASSWD_EXP_DATE"
type="java.sql.Timestamp"
not-null="false"
length="19"
/>
<property
name="userPassword"
column="USER_PASSWORD"
type="java.lang.String"
not-null="true"
length="50"
/>
</class>
</hibernate-mapping>


Full stack trace of any exception that occurs:
org.hibernate.MappingException: could not instantiate id generator
at org.hibernate.id.IdentifierGeneratorFactory.create(IdentifierGeneratorFactory.java:99)
at org.hibernate.mapping.SimpleValue.createIdentifierGenerator(SimpleValue.java:111)
at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:168)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1031)
at com.wos.hibernate.util.base._BaseRootDAO.initialize(_BaseRootDAO.java:52)
at com.wos.hibernate.util.base._BaseRootDAO.initialize(_BaseRootDAO.java:40)
at com.wos.hibernate.util.base._BaseRootDAO.initialize(_BaseRootDAO.java:31)
at com.wos.hibernate.util.dao.PmUserDAO.<clinit>(PmUserDAO.java:16)
at com.wos.dao.AdminDAO.loginValidate(AdminDAO.java:599)
at com.wos.bean.AdminBean.loginValidate(AdminBean.java:169)
at com.wos.bean.WOSAdmin_whklez_EOImpl.loginValidate(WOSAdmin_whklez_EOImpl.java:46)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.apache.axis.providers.java.RPCProvider.invokeMethod(RPCProvider.java:383)
at org.apache.axis.providers.java.RPCProvider.processMessage(RPCProvider.java:291)
at org.apache.axis.providers.java.JavaProvider.invoke(JavaProvider.java:330)
at org.apache.axis.strategies.InvocationStrategy.visit(InvocationStrategy.java:71)
at org.apache.axis.SimpleChain.doVisiting(SimpleChain.java:150)
at org.apache.axis.SimpleChain.invoke(SimpleChain.java:120)
at org.apache.axis.handlers.soap.SOAPService.invoke(SOAPService.java:475)
at org.apache.axis.server.AxisServer.invoke(AxisServer.java:323)
at org.apache.axis.transport.http.AxisServlet.doPost(AxisServlet.java:854)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
at org.apache.axis.transport.http.AxisServletBase.service(AxisServletBase.java:339)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run(ServletStubImpl.java:1053)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:387)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:305)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:6310
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:317)
at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:118)
at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3622)
at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2569)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:197)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:170)
Caused by: java.lang.ClassNotFoundException: vm
at java.net.URLClassLoader$1.run(URLClassLoader.java:199)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:187)
at java.lang.ClassLoader.loadClass(ClassLoader.java:289)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:274)
at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:302)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:141)
at org.hibernate.util.ReflectHelper.classForName(ReflectHelper.java:103)
at org.hibernate.id.IdentifierGeneratorFactory.create(IdentifierGeneratorFactory.java:93)

Name and version of the database you are using: Oracle 9

Do you have the dialect specified for your database? in the hibernate.cfg.xml file?