don't let the node move to the border limit exactly. You should write, e.g.,: $node($i) setdest [expr $x-0.01] $y $vitess
or extend your area limit a little bit. Good Luck, Samer > ----- Original Message ----- > From: "amira bourayou" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]>; <ns-users@ISI.EDU> > Sent: Tuesday, February 06, 2007 6:49 PM > Subject: [ns] need EMERGENCY HELP PLZ segmentation fault pbm > > >> >> hi every one! >> when i use >> $node($i) setdest $x $y $vitess >> i got the following error:*segmentation fault* when i run my script. >> >> how to repare this? >> >> please help me.it's urgent. >> >> best regards. >