$mech->add_header( accept_language => 'de');

$mech->add_header( 'accept-language' => 'de');

$mech->click_button( name => "dl.start",
                        value => "Free"
 );

E:\perl>perl mech.pl
Can't locate object method "click_button" via package "WWW::Mechanize" at
        mech.pl line 13 (#1)
    (F) You called a method correctly, and it correctly indicated a package
    functioning as a class, but that package doesn't define that particular
    method, nor does any of its base classes.  See perlobj.

Uncaught exception from user code:
        Can't locate object method "click_button" via package "WWW::Mechanize" a
t mech.pl line 13.
 at mech.pl line 13

C:\Dokumente und Einstellungen\ich>perl -e "use WWW::Mechanize 999"
WWW::Mechanize version 999 required--this is only version 0.72 at -e line 1.
BEGIN failed--compilation aborted at -e line 1.