sub login()
{
    $mech->get($loginPage);
    $mech->set_visible($email, $pass);
    #
    # the original line, below, has double quotes nested
    # within single quotes
    #
    #$mech->click_button('value'=>'"Sign in using our secure server"');
    # no error if you remove them
    $mech->click_button('value'=>'Sign in using our secure server');
    
}