I am new to nHibernate, so hopefully this is not to much of a newb question. I am trying to get my first C# .Net3.5 nHibernate Oracle 10g
application running. To get started I have set it to do something
pretty simple, at least I thought.

Here is my hibernate.cfg.xml file:
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-configuration xmlns="urn:nhibernate-configuration-2.2">

<!-- an ISessionFactory instance -->
<session-factory>

<!-- properties -->
<property name="connection.provider">NHibernate.Connection.D
riverConnectionProvider</property>
<property name="connection.driver_class">NHibernate.Driver.O
racleDataClientDriver</property>
<property name="connection.connection_string">User
ID=id;Password=pw;Data Source=requ;Pooling=true;Connection
Lifetime=180;Connection Timeout=30;Min Pool Size=2;Max Pool
Size=10;Incr Pool Size=2;</property>
<property name="dialect">NHibernate.Dialect.Oracle10gDialect </
property>
<property name="show_sql">true</property>

<!-- mapping files -->
<mapping resource="DataLayer.Mappings.Audit.hbm.xml"
assembly="DataLayer" />
</session-factory>

</hibernate-configuration>

Audit.hbm.xml:
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
assembly="DataLayer" namespace="DataLayer">
<class name="DataLayer.DAO.Audit, DataLayer" table="ws_audit">
<id name="id" type="int" column="ws_audit_id">
<generator class="native" />
</id>
<property name="originalXml" type="string" column="original_xml"/>
</class>
</hibernate-mapping>

The class is pretty simple:
using System;
using System.Collections.Generic;
using System.Text;

namespace DataLayer.DAO
{
public class Audit
{
private int id;

public int Id
{
get { return id; }
set { id = value; }
}

private string originalXml;

public string OriginalXml
{
get { return originalXml; }
set { originalXml = value; }

}
}
}

And I have a simple aspx, here is the code-behind:
Audit auditInstance;

protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
IList auditList;
ISessionFactory factory = new
NHibernate.Cfg.Configuration().Configure().BuildSe ssionFactory();
using (ISession session = factory.OpenSession())
{
ICriteria ac = session.CreateCriteria(typeof(Audit));
auditList = ac.List();
session.Close();
}

factory.Close();
auditInstance = (Audit)auditList[0];
txtId.Text = auditInstance.Id.ToString();
txtOrigXml.Text = auditInstance.OriginalXml;

}
}

When I attempt to run I get: Could not compile the mapping document:
DataLayer.Mappings.Audit.hbm.xml

And my error page looks like:
Server Error in '/' Application.
--------------------------------------------------------------------------------

Could not load type NHibernate.Dialect.Oracle10gDialect. Possible
cause: no assembly name specified.
Description: An unhandled exception occurred during the execution of
the current web request. Please review the stack trace for more
information about the error and where it originated in the code.

Exception Details: System.TypeLoadException: Could not load type
NHibernate.Dialect.Oracle10gDialect. Possible cause: no assembly name
specified.

Source Error:

Line 20: {
Line 21: IList auditList;
Line 22: ISessionFactory factory = new
NHibernate.Cfg.Configuration().Configure().BuildSe ssionFactory();
Line 23: using (ISession session = factory.OpenSession())
Line 24: {

Source File: C:\temp\UsingSpring\UsingSpring\TestAudit.aspx.cs Line:
22

Stack Trace:

[TypeLoadException: Could not load type
NHibernate.Dialect.Oracle10gDialect. Possible cause: no assembly name
specified.]
NHibernate.Util.ReflectHelper.TypeFromAssembly(Ass
emblyQualifiedTypeName name, Boolean throwOnError) +653
NHibernate.Util.ReflectHelper.ClassForName(String name) +70
NHibernate.Dialect.Dialect.InstantiateDialect(Stri ng dialectName) +65

[HibernateException: Could not instantiate dialect class
NHibernate.Dialect.Oracle10gDialect]
NHibernate.Dialect.Dialect.InstantiateDialect(Stri ng dialectName)
+199
NHibernate.Dialect.Dialect.GetDialect(IDictionary` 2 props) +233
NHibernate.Cfg.Configuration.AddValidatedDocument( NamedXmlDocument
doc) +163

[MappingException: Could not compile the mapping document:
DataLayer.Mappings.Audit.hbm.xml]
NHibernate.Cfg.Configuration.LogAndThrow(Exception exception) +107
NHibernate.Cfg.Configuration.AddValidatedDocument( NamedXmlDocument
doc) +369
NHibernate.Cfg.Configuration.ProcessMappingsQueue( ) +51
NHibernate.Cfg.Configuration.AddDocumentThroughQue ue(NamedXmlDocument
document) +53
NHibernate.Cfg.Configuration.AddXmlReader(XmlReade r hbmReader, String
name) +72
NHibernate.Cfg.Configuration.AddInputStream(Stream xmlInputStream,
String name) +159
NHibernate.Cfg.Configuration.AddResource(String path, Assembly
assembly) +268
NHibernate.Cfg.Configuration.DoConfigure(IHibernat eConfiguration hc)
+993
NHibernate.Cfg.Configuration.Configure(XmlReader textReader) +315
NHibernate.Cfg.Configuration.Configure(String fileName, Boolean
ignoreSessionFactoryConfig) +173
NHibernate.Cfg.Configuration.Configure(String fileName) +45
NHibernate.Cfg.Configuration.Configure() +177
UsingSpring.TestAudit.Page_Load(Object sender, EventArgs e) in C:\temp
\UsingSpring\UsingSpring\TestAudit.aspx.cs: 22
System.Web.Util.CalliHelper.EventArgFunctionCaller (IntPtr fp, Object
o, Object t, EventArgs e) +14
System.Web.Util.CalliEventHandlerDelegateProxy.Cal lback(Object
sender, EventArgs e) +35
System.Web.UI.Control.OnLoad(EventArgs e) +99
System.Web.UI.Control.LoadRecursive() +50
System.Web.UI.Page.ProcessRequestMain(Boolean
includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
+627

--------------------------------------------------------------------------------
Version Information: Microsoft .NET Framework Version:2.0.50727.3603;
ASP.NET Version:2.0.50727.3053

Any ideas?
Thanks, Sammer