About tcl debugging

[syan@jupiter.nal.utoronto.ca (Shuqian Yan)]

Hello, all

Does anyone has experience on how to use the tcl debugger? I am using the tcl-debug-1.9 now. In my simulation script, I has added the line debug 1. And in executing the script, I use ns D -1 example.tcl, after this, there was a command prompt %, 
So I guess I am in the debugging mode already, however when I type h for "help",
it simply repeats 1 h, I guess "1" stands for the evaluation stack level, but when I type n to step over the procedures, it says:

ambiguous command name "n": namespace networkinterface new ns ns-random ns-version ns_class_maxIdle ns_class_params ns_connect ns_create_cbr ns_create_class ns_create_class1 ns_create_connection ns_duplex ns_simplex

All the other commands I tried gave similar statement, complaining about ambiguous command name. 

Could anyone of you who is experience with tcl-debugger give me some hints on how to make it work for me?

Tks,

shuqian