Hi!!!! I have got the answer for the previous problem. But now my code is giving another problem. My protocol implementation is successful but it is giving following error when i use it in setup. (_o17 cmd line 1) invoked from within "_o17 cmd if-queue _o20" invoked from within "catch "$self cmd $args" ret" invoked from within "if [catch "$self cmd $args" ret] { set cls [$self info class] global errorInfo set savedInfo $errorInfo error "error when calling class $cls: $args" $..." (procedure "_o17" line 2) (SplitObject unknown line 2) invoked from within "$agent if-queue [$self set ifq_(0)] " (procedure "_o14" line 18) (Node/MobileNode add-target line 18) invoked from within "$self add-target $agent $port" (procedure "_o14" line 15) (Node attach line 15) invoked from within "$node attach $ragent [Node set rtagent_port_]" (procedure "_o3" line 78) (Simulator create-wireless-node line 78) invoked from within "_o3 create-wireless-node" ("eval" body line 1) invoked from within "eval $self create-wireless-node $args" (procedure "_o3" line 23) (Simulator node line 23) invoked from within "$ns_ node" ("for" body line 2) invoked from within "for {set i 0} {$i < $val(nn) } {incr i} { set node_($i) [$ns_ node] $node_($i) random-motion 0 # disable random motion }" Pse help me for the same at the earliest as it is required for my project. Regards Namita ________________________________ Download prohibited? No problem. CHAT from any browser, without download. Check out the all-new Messenger 9.0! Go to http://in.messenger.yahoo.com/