[panse@localhost ns-2.30]$ ./ns
% ns example1.tcl
error when calling class OldSim: example1.tcl
% cat example1.tcl
set ns [ new Simulator ]
set nf [ open out.nam w ]
$ns namtrace-all $nf
proc finish { }
{
global ns nf
$ns flush-trace
close $nf
exec nam out.name &
exit 0
}
set n0 [ $ns node ]
set n1 [ $ns node ]
$ns duplex-link $n0 $n1 10ms DropTail
$ns at 5.0 "finish"
$ns run
%

my .tcl files are placed in /n-2.30/tcl/ex directory

my ns version is ns-2.30

tell me the step by step solution to solve this...

i am new to ns

thnx in advance