[ns] really need help for timers

[Kai Li <kli@uncc.edu>]

Hi,All!

I am stucking into the timer for a long time. Really need people to help.

In Mac-802_11.cc, I define my own timer(almost same as recv timer), then in the 
program, I use the following two statements:

...
mhTimer.start(mhRecv.expire());
mhTimer.start(TX_Time(p));
...

I try to schedule two different events using the same timer at the same time but 
it gives me problem. I would greatly appreciate any help and advice.

KL,