Invalid XML: jbosscmp-jdbc.xml while deploy in Jboss 4?

I am trying to deploy my J2EE application. In my app, I used CMP so there is a need of jbosscmp-jdbc.xml file. Howerver, when I tr开发者_开发问答ied to deploy my app in the Jboss, I got the follwing exception:

 org.jboss.deployment.DeploymentException: Invalid XML:....
!/META-INF/jbosscmp-jdbc.xml; - nested throwable:
    ....
    The content of element type "entity" must match "(ejb-name,datasource?,datasource-mapping?,create-table?,remove-table?,post-table-create?,read-only?,read-time-out?,row-locking?,pk-constraint?,read-ahead?,list-cache-max?,clean-read-ahead-on-load?,fetch-size?,table-name?,cmp-field*,load-groups?,eager-load-group?,lazy-load-groups?,query*,unknown-pk?,entity-command?,optimistic-locking?,audit?)".)
    .......
    Caused by: org.xml.sax.SAXParseException: The content of element type "entity" must match "....

Here is the content of jbosscmp-jdbc.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE jbosscmp-jdbc PUBLIC
"-//JBoss//DTD JBOSSCMP-JDBC 4.0//EN"
"http://www.jboss.org/j2ee/dtd/jbosscmp-jdbc_4_0.dtd" >

<jbosscmp-jdbc>
    <defaults>
        <datasource>Java:/BeansDemoDB</datasource>
        <datasource-mapping>MS SQLSERVER</datasource-mapping>
        <create-table>false</create-table>
    </defaults>
    <enterprise-beans>
        <entity>
            <ejb-name>TUsers</ejb-name>
            <table-name>T_Users</table-name>
            <cmp-field>
                <field-name>username</field-name>
                <column-name>username</column-name>
            </cmp-field>
            <cmp-field>
                <field-name>password</field-name>
                <column-name>password</column-name>
            </cmp-field>
            <cmp-field>
                <field-name>role</field-name>
                <column-name>role</column-name>
            </cmp-field>
        </entity>
        <entity>
            <ejb-name>TStudents</ejb-name>
            <table-name>T_Students</table-name>
            <abstract-schema-name>TStudents</abstract-schema-name>
            <cmp-field>
                <field-name>studentID</field-name>
                <column-name>studentID</column-name>
            </cmp-field>
            <cmp-field>
                <field-name>studentName</field-name>
                <column-name>studentName</column-name>
            </cmp-field>
        </entity>
    </enterprise-beans>
</jbosscmp-jdbc>

I have tried to deploy in both Jboss 4 and 5, but got the same error. Have tried to google this but no luck. What's wrong with my jbosscmp-jdbc.xml?

Found bug in my jbosscmp-jdbc.xml, Remove the element: <abstract-schema-name>TStudents</abstract-schema-name> in the entity TStudents.

Thanks all for reading my question.