if [[ $# != 4 ]] 
then
   echo Usage: $0  FlowID  SourceNode DestinationNode TraceFile
   echo "  " FlowID is set by using \$tcp set fid ... in NS2
   echo "  " Source Node depends on the order you create the Nodes in NS
   echo "  " Destination Source Node depends on the order you create Nodes in NS
   exit 1
fi

gawk -f /home/cheung/teaching/web/558/Syllabus/Tools/delay.awk \
   flow=$1 src=$2 dst=$3 $4