于关cfg.AddResource("Mapping.DataEntity.hbm."+files[i],Assembly.Load("Mapping.DataEntity"));出错的问题求救.

我在用写持久层时对于标有箭头的这个方法出现了错误:
        private static void BuildSessionFactory()
        {
            ExportSchema(new string[]{
                                            "users.hbm.xml",
                                            "guestbook.hbm.xml"
                                        },false);
        }        private static void ExportSchema(string[] files,bool exportschema)
        {
            cfg=new Configuration();
            for(int i=0;i<files.Length;i++)
            {
                ------->>cfg.AddResource("Mapping.DataEntity.hbm."+files[i],Assembly.Load("Mapping.DataEntity"));
            }            dialect=Dialect.GetDialect();
            if(exportschema) new SchemaExport(cfg).Create(true,true);            sessions=cfg.BuildSessionFactory();
        }
错误提示如下:
File or assembly name Mapping.DataEntity, or one of its dependencies, was not found. 
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.IO.FileNotFoundException: File or assembly name Mapping.DataEntity, or one of its dependencies, was not found.Source Error: 
Line 51:             for(int i=0;i<files.Length;i++)
Line 52:             {
Line 53:                 cfg.AddResource("Mapping.DataEntity.hbm."+files[i],Assembly.Load("Mapping.DataEntity"));
Line 54:             }
Line 55: 
 
-------------------------我的users.hbm.xml代码,另外一个也是如此-----------------------
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
<class name="Mapping.DataEntity.users, Mapping.DataEntity" table="G_users">
<id name="id" column="id" type="Int32">
<generator class="identity" />
</id>
<property name="Name" type="String(20)" column="Name" />
<property name="email" type="String(40)" column="email" />
<property name="password" type="String(20)" column="password" />
<property name="flag" type="Int32" column="flag" />
<property name="regtime" type="DateTime" column="regtime" />
</class>
</hibernate-mapping>
--------------------------------------------------------------------------请问是怎么回事呀,是不是还和名字间也有关系的呢?迷糊了.