the "use vars" and "use subs" declarations are not BLOCK-scoped.  
They are thus effective for the entire file in which
they appear. 

##</code><code>##

 use strict;

$\="\n";
use vars qw($x);
$x="main";
{

    print $x;
    package one;
    use vars qw($x);
    $x="one";
    print $x;
}

print $x;
__END__
main
one
main