question about agent type

["Robin POSS" <robinposs@lemel.fr>]

Hello,

I would like to develop an agent for ad-hoc network which runs a 
neighbor discovery protocol, and just that.
As the aodv routing protocol does neighbor discovery, my code-writing 
strategy has been to steal as much as I could into the aodv code.
But, I want my new agent, call it nbd, to be a normal agent, not a 
routing one like aodv. However, I would like nbd to send its packets  
(hello messages in fact) direclty to the ll layer.
To do so, I think I should add to the add-target-New procedure in ns/tcl
/lib/ns-node.tcl the following:

	#
	# Send Target
	#

If the agent is a nbd
	$agent target [$self set ll_(0)]
else
	$agent target [$self entry]
	
	#
	# Recv Target
	#
	...

How could I code the "agent is a nbd" part?
How could I get the type of an agent when the only thing I know about it
 is "$agent"?

any suggestions about how I could do what I want to do?

Cheers,
--
Robin POSS