groovy syntax error....

groovy

    stage ('Cleaning') {
      steps {
        /*echo "cleaning"*/
        if (env.BRANCH_NAME == 'Trunk') {
          sh "xbuild /p:Configuration=${env.TRUNK_BUILD_CONFIGURATION} /t:Clean ${env.SOLUTION_NAME}"
        } else {
          sh "xbuild /p:Configuration=${env.RELEASE_BUILD_CONFIGURATION} /t:Clean ${env.SOLUTION_NAME}"
        }
        echo "cleaning complete"
      }
    }