Nant Build script undifined Issue

I have the following code in a nant build script:

<project name="fgs">
 <property name="build.dir" value="build"/>
 <property name="build.bin.dir" value="${build.dir}/bin"/>

 <fileset id="provider.1.0-references" basedir="${build.bin.dir}">
   <include name="thenameofadllfile.*"/>
 </fileset>

  <macrodef name="build-dist">
   <attributes>
    <attribute name="version"/>
    <attribute name="service.references"/>
    <attribute name="release.type"/>
   </attributes>

 <sequential>     
  <echo message="service.references: ${service.references}" />
  <copy todir="${build.dist.dir}/server/${version}/${release.type}/bin" >
  开发者_StackOverflow社区<fileset refid="@{service.references}" casesensitive="false" />
  </copy>
 </sequential>
</macrodef>


<target name="create-dist">
  <server-staging-dist release.type="staging" version="1.0" service.references="service.1.0-references" />
</target>

however when i run this code I get: fileset reference '@{service.references}' is not defined.

i have tried it with changing the doller sign for the @ symbol. Not sure what the difference is?

Thanks in advance for any help or advice given.

Try <fileset refid="provider.1.0-references" casesensitive="false" />