grml-wallpaper() { 
    if [ -f /usr/share/grml/"$1" ] ; then
       Esetroot -scale /usr/share/grml/"$1"
    else
       Esetroot -scale $*
    fi
  }

  _grml-wallpaper() {
    dirs=(. /usr/share/grml/)
    _description files expl 'set desktop wallpaper on grml system'
    _files "$expl[@]" -W dirs -g '*.{jpg,png}(-.)'
  }
  compdef _grml-wallpaper grml-wallpaper