import VirtualMailManager as VMM

    def __init__(self, dbh, domainname, targetDomain=None):

        self.__name = VMM.VirtualMailManager.chkDomainname(domainname)

        self.__gid = 0

        self._domain = targetDomain

        self._exists()

        dbc = self._dbh.cursor()

        dbc.execute('SELECT gid, is_primary FROM domain_name WHERE domainname\

 = %s', self.__name)

        alias = dbc.fetchone()

        dbc.close()

        if alias is not None:

            self.__gid, primary = alias

            if primary:

                raise VDAE(_(u"The domain »%s« is a primary domain.") %

                        self.__name, ERR.DOMAIN_ALIAS_ISDOMAIN)

        if self.__gid > 0:

            raise VDAE(_(u'The domain alias »%s« already exists.') %self.__name,

                ERR.DOMAIN_ALIAS_EXISTS)

        if self._domain is None:

            raise VDAE(_(u'No destination domain for alias domain denoted.'),

                    ERR.DOMAIN_ALIAS_NO_DOMDEST)

        if self._domain._id < 1:

            raise VDAE (_(u"The target domain »%s« doesn't exist yet.") %

                    self._domain._name, ERR.NO_SUCH_DOMAIN)

        dbc = self._dbh.cursor()

        dbc.execute('INSERT INTO domain_name (domainname, gid, is_primary)\

 VALUES (%s, %s, FALSE)', self.__name, self._domain._id)

        self._dbh.commit()

        dbc.close()

        if self.__gid > 0:

            dbc = self._dbh.cursor()

            dbc.execute('SELECT domainname FROM domain_name WHERE gid = %s\

 AND is_primary', self.__gid)

            domain = dbc.fetchone()

            dbc.close()

            if domain is not None:

                return _(u"The domain alias »%(alias)s« belongs to »%(dom)s«.")\

                        % {'alias': self.__name, 'dom': domain[0]}

            else:# an almost unlikely case, isn't it?

                raise VDAE(

                    _(u'There is no primary domain for the domain alias »%s«.')\

                            % self.__name, ERR.NO_SUCH_DOMAIN)

        else:

            raise VDAE(

                  _(u"The domain alias »%s« doesn't exist yet.") % self.__name,

                  ERR.NO_SUCH_DOMAIN_ALIAS)

        if self.__gid > 0:

            dbc = self._dbh.cursor()

            dbc.execute('DELETE FROM domain_name WHERE domainname = %s \

 AND NOT is_primary', self.__name)

            if dbc.rowcount > 0:

                self._dbh.commit()

        else:

            raise VDAE(

                  _(u"The domain alias »%s« doesn't exist yet.") % self.__name,

                  ERR.NO_SUCH_DOMAIN_ALIAS)