[ns] Error after loading mobility scenario file

[Puneet Agrawal]

Hello everyone!
I am getting following error on terminal after loading scenario file;

can't read "node_(0)": no such variable

    while executing
"$node_(0) set X_ 220.862351576651"
    (file "puneet" line 4)
    invoked from within
"source.orig puneet"
    ("uplevel" body line 1)
    invoked from within
"uplevel source.orig [list $fileName]"
    invoked from within
"if [$instance_ is_http_url $fileName] {
set buffer [$instance_ read_url $fileName]
uplevel eval $buffer
} else {
uplevel source.orig [list $fileName]
..."
    (procedure "source" line 8)
    invoked from within
"source "puneet""
    (file "scene1.tcl" line 329)

Regards 
Puneet Agrawal