retrieving database schema using ant task

[Sheeba]

Hi
 
I am new to ddlutils.I am connecting to sql server which has a database
testdb and it has two tables customer and orders.I am trying to retrieve
these information using ddlutils ant task.I am using the code given at the
website to retrieve database schema using ant task. When I build this,I get
the file "db-schema.xml' which has only line and says <database/>.
Could any body help me solving the problem
 
Thanks
sheeba
 
<path id="runtime.classpath">
  <fileset dir="lib">
    <include name="**/*.jar"/>
    <include name="**/*.zip"/>
  </fileset>
</path>
 
<target name="database-dump" description="Dumps the database structure">
  <taskdef name="databaseToDdl"
           classname="org.apache.ddlutils.task.DatabaseToDdlTask">
    <classpath refid="runtime-classpath"/>
  </taskdef>
  <databaseToDdl>
<database url="jdbc:microsoft:sqlserver://demo:1433;DatabaseName=testdb"
              driverClassName="com.microsoft.jdbc.sqlserver.SQLServerDriver"
              username="user"
              password="user123"/>
    <writeSchemaToFile outputFile="db-schema.xml"/>
  </databaseToDdl>
</target>