select one ghostscript on ubuntu 6.10

I installed three different versions of ghostscript as following

apt-cache policy gs-esp
gs-esp:
  Installed: 8.15.2.dfsg.0ubuntu1-0ubuntu4
  Candidate: 8.15.2.dfsg.0ubuntu1-0ubuntu4
  Version table:
 *** 8.15.2.dfsg.0ubuntu1-0ubuntu4 0
        500 http://archive.ubuntu.com edgy/main Packages
        100 /var/lib/dpkg/status

apt-cache policy gs-gpl
gs-gpl:
  Installed: 8.50-1.1ubuntu1
  Candidate: 8.50-1.1ubuntu1
  Version table:
 *** 8.50-1.1ubuntu1 0
        500 http://archive.ubuntu.com edgy/main Packages
        100 /var/lib/dpkg/status

apt-cache policy gs-afpl
gs-afpl:
  Installed: 8.14-3.1
  Candidate: 8.14-3.1
  Version table:
 *** 8.14-3.1 0
        500 http://archive.ubuntu.com edgy/multiverse Packages
        100 /var/lib/dpkg/status

It can be selected with followiing command

update-alternatives --config gs

There are 3 alternatives which provide `gs'.

  Selection    Alternative
-----------------------------------------------
*+        1    /usr/bin/gs-esp
          2    /usr/bin/gs-gpl
          3    /usr/bin/gs-afpl

Press enter to keep the default[*], or type selection number: 2
Using `/usr/bin/gs-gpl' to provide `gs'.