proc person1 {x} {
  global ns

  puts "Person 1:"
  puts " Hey, $x, time is [$ns now], it's your turn to say something"
  $ns  at  [expr [$ns now] + 0.4]  "$x person1"
}

proc person2 {x} {
  global ns

  puts "Person 2:"
  puts " Hey, $x, time is [$ns now], it's your turn to say something"
  $ns  at  [expr [$ns now] + 0.6]  "$x person2"
}

set  ns  [new Simulator]
$ns  at  0  "person1 person2"
$ns  at  4.5 "exit 0"


$ns run