JTA的配置问题

<?xml version="1.0" encoding="UTF-8"?>
<datasources>
  <xa-datasource>
    <jndi-name>MySqlXADS</jndi-name>
    <xa-datasource-class>com.mysql.jdbc.jdbc2.optional.MysqlXADataSource</xa-datasource-class>
    <xa-datasource-property name="Url">jdbc:mysql://127.0.0.1:3306/testdb</xa-datasource-property>
    <xa-datasource-property name="User">root</xa-datasource-property>
    <xa-datasource-property name="Password">root</xa-datasource-property>
  <user-name>root</user-name>
    <password>root</password>
  <exception-sorter-class-name>org.jboss.resource.adapter.jdbc.vendor.MySQLExceptionSorter</exception-sorter-class-name>
    <metadata>
       <type-mapping>mySQL</type-mapping>
    </metadata>
  </xa-datasource>
</datasources>
<p class="indent">

<bean id="dataSourceForMysql" class="org.springframework.jndi.JndiObjectFactoryBean">
    <property name="jndiName">
      <value>java:/MySqlXADS</value>
    </property>
</bean>
<p class="indent">

Error creating bean with name 'dataSourceForMysql' defined in file [E:\jboss-4.0.4RC1\server\default\deploy\zjtest.war\WEB-INF\classes\spring-jta.xml]: Initialization of bean failed; nested exception is javax.naming.NameNotFoundException: MySqlXADS not bound
<p class="indent">

<p class="indent">[ConnectionFactoryBindingService] Bound ConnectionManager 'jboss.jca:service=DataSourceBinding,name=MySqlXADS' to JNDI name 'java:MySqlXADS'
<p class="indent">