hi all in emulation,I want to give different delay at different time using the following: $ns at $time1 "$ns simplex-link $node0 $node1 100MB $owdelay1 DropTail" $ns at $time2 "$ns simplex-link $node0 $node1 100MB $owdelay2 DropTail" but it's wrong i do not know how to correct it? thx