[ns] Nam question.

[Guang Zeng <zeng.guang@verizon.net>]

I am doing simulation of Mobile IP.

I wrote below codes:
set topo [new opography]
$topo load_flatgrid 670 670

$HA set X_ 1.0
$HA set Y_ 1.0
$HA set Z_ 0.0

$FA set X_ 600.0
$FA set Y_ 600.0
$FA set Z_ 0.0

$MH set X_ 1.0
$MH set Y_ 1.0
$MH set X_ 0.0

$ns at 100.0 "$MH setdest 600.0 600.0 20.0"

But, when run nam:
                               MH(move)
     X                        /
     |                      /
     |                    /
    / \                 /
   FA  HA             /
       MH(at time 0)/

It supposed should moved between two agents, but..../