use base qw(Net::FTP);   #5.8

#or for 5.10 and up
#use parent qw(Net::FTP);

sub new {
  my ($pkg, $server, $user, $timeout, @args) = @_;

  # some special class specific stuff

  # ... is params for super class structure
  my $self = $pkg->SUPER::new(...); 
  $self->server($server);
  $self->user($user);
  $self->timeout($timeout);
  $self->initialize();

  # some special class specific stuff

  # if SUPER::new is well behaved, $self will be a member
  # of the $pkg class even though it was built by the
  # the super class.
  return $self;
}