Hi Monks, I have fixed the issue by adding some headers . Now its working fine.

#!/usr/bin/perl -w

use strict;
use WWW::Mechanize;
use HTML::TreeBuilder;
use Data::Dumper;


my $mech = WWW::Mechanize->new();
my $url = 'http://www.etfsecurities.com/en/etfscalculations/etfsmsl.as
+px?region=us';

$mech->agent_alias('Windows Mozilla');
$mech->add_header('Host' => 'www.etfsecurities.com');
$mech->add_header('Accept' => 'text/html,application/xhtml+xml,applica
+tion/xml;q=0.9,*/*;q=0.8');
$mech->add_header('Accept-Language' => 'en-us,en;q=0.5');
$mech->add_header('Accept-Encoding' => 'gzip, deflate');
$mech->add_header('Connection' => 'keep-alive');
$mech->add_header('Cache-Control' => 'private');
$mech->add_header('Content-Type' => 'text/html; charset=utf-8');

$mech->get($url);


print $mech->content();

open(WRT,">praveenzx.htm");
print WRT $mech->content();
close(WRT);
[download]

thanks for you advice, praveenzx~