[ns] How do I stop FTP in a wireless simulation?

[Jonathan Arnold]

Hello people,

I have a wireless simulation running under Cygwin on Win XP using ns 2.27.

Currently I have two ftp session sending packets and one seems to be 
dominating the RF environment. As such I would like to stop this one session 
using:

$ns_ at 80.0 "ftp_(0) stop" 

but ns responds with an invalid command name?

How do I terminate this flow of traffic? I searched the archive and found a 
similar problem but unfortunately that email could not be read so I am stuck 
now.

Any help would be greatly appreciated; I am very new to NS.

Thanks

Jon