[ns] Installation problems with ns-2.33

[Siraj Shaikh]

I installed ns-2.33 on my machine (Ubuntu). Followed the intstructions
on here: http://nsnam.isi.edu/nsnam/index.php/Installing_ns2.31_on_Ubuntu7.04

Everything worked fine and as expected. No errors encountered.

I the validation set up and even the path/environment variables. Have
checked the paths since then and they are all fine.

The problem: for any file xxx.tcl (in the right folder) every time I type

$ ns xxx.tcl

I get

$ xxx.tcl does not exist, try again

Why? When I type

$ ns

I get

Usage:      host [-v] [-a] [-t querytype] [options]  name  [server]
Listing:    host [-v] [-a] [-t querytype] [options]  -l zone  [server]
Hostcount:  host [-v] [options] -H [-D] [-E] [-G] zone
Check soa:  host [-v] [options] -C zone
Addrcheck:  host [-v] [options] -A host
Listing options: [-L level] [-S] [-A] [-p] [-P prefserver] [-N skipzone]
Common options:  [-d] [-f|-F file] [-I chars] [-i|-n] [-q] [-Q] [-T] [-Z]
Other options:   [-c class] [-e] [-m] [-o] [-r] [-R] [-s secs] [-u] [-w]
Special options: [-O srcaddr] [-j minport] [-J maxport]
Extended usage:  [-x [name ...]] [-X server [name ...]]

What is the problem? Please help!