Urgent help: Wrong node routing agent

[newbie06]

Hi everybody

Linux and tcl are my new platform of operating system. So I am still in the process of learning and adapting. I am using network simulator 2 as my simulator and now I am having problem with my tcl script in which during the simulation process, I got not the output, but the following message:

Num_node is set to 4
Wrong node routing agent!

oo..I forgot to mention that before this happened, I have been warned about the syntax error message in the following sentence:

set l2lat [lindex $argv 5]
set addrlatency [lindex $argv 6]
set l2latency [expr [string trim $l2lat "ms"] + [string trim $addrlatency "ms"] ]ms

I have checked my script and I think everything is just working fine. But it is not!. Please someone help me..I really need to solve these out. I just want to know what has cause those two errors (syntax and routing agent) error message to occur and what will be the possible solution to solve the problem.

Thanks in advance for your help.