use HTTP::Cookies::Netscape;
my $cookie_jar = HTTP::Cookies::Netscape->new(
    file => 'E:/lwp_cookies.dat',
    autosave => 1,
);

my $mech = WWW::Mechanize->new(
    agent => 'Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)',
    cookie_jar => $cookie_jar,
    stack_depth => 1,
    autocheck => 1,
);