--Code--

use WWW::Mechanize;
use HTTP::Cookies;
use threads;

$|=1;
my $cookie_jar = HTTP::Cookies->new;
$mech = WWW::Mechanize->new( 
agent => 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:21.0)',
 cookie_jar => $cookie_jar, 
 timeout    => "15",
 autocheck  => 0);
                                
$url = 'http://www.fwrd.com/product-military-boots/YEF3-MZ2/'; 
# page will default to error page if not around...

$delay = 15;

check();

sub check {
 print "[x] starting...\n";
 
while(1) {
 
 $resp = $mech->get($url);
 
 if((!$resp->is_success) || ($resp->request->uri =~ m/error/i)) { 
   print "."; }

 else {
  
 
 for $sz (1..5) {
 
  $thread = threads->new( sub { notify_plz($sz) });
         my $tid = $thread->tid;
         push (@Threads, $thread);   
        $thread->detach();          
 }
 
 
         
 # we saw the page , exit
 exit;
 
 # end what we do if its found
 }
 
 sleep $delay;
  }
 }