[ns] how to use print instead of trace?

[Ines Kechiche]

As I got error  no-slot{} default handler while trying to trace sctp trafic
with
set trace_ch [open trace.sctp w]
$sctp0 set trace_all_ 1           # trace them all on oneline
$sctp0 trace cwnd_
$sctp0 trace rto_
$sctp0 trace errorCount_
$sctp0 attach $trace_ch

I tried to substitute *"trace**"* with *"print"* but I don't know actually
how does it works.
shall I add time? And in which file will the values be printed. is it *
"all.nam"* or *"all.tr"*?
Does anyone have an idea?