#!"C:\perl\bin\perl.exe"
use strict;
use warnings;
use HTTP::Cookies;
use LWP::UserAgent;
my $ua = LWP::UserAgent->new;
$ua->cookie_jar(HTTP::Cookies->new(file => "cookie2.txt",autosave => 1,));
my $url_base = "http://www.host.com/login.php";
my $response = $ua->get($url_base);
my $contenu = $response->content;
$content =~ s/\n//g;#extracting session id
my @sids = split(/sid=/,$content);
my $id;
shift(@sids);
foreach $id(@sids){
    $id =~ s!"(.*)!!;
}
my $res = $ua->post ($url_base.'?sid='.$sids[0],[username => 'myUserName', password=>'myPassword',login=>'Connexion']);