remove line around the graph

Hi again,
Will be better with a subject,
(sorry for the pollution)

  I'm looking for a way to remove and/or control the properties (color,
thickness,...) of the lines (axis) around the graph.
I spent already quite some time to search a solution. I have found only one
comment on these lines in the multiline-plot wiki:
"It's on our list of things to change the way these axes lines are draw
so that you can remove it, but it isn't done yet"

Is this done now? Is there even a dirty trick to at least remove them?