function _filter($filter)
{
$filter['to_type'] = 1;
$where[] = 'folder = \'inbox\'';
$where[] = 'for_id = 0';
$where[] = 'rel_order = 0';
if ($filter['msg_from']) {
$where[] = "msg_from ='" . addslashes($filter['msg_from']) . "'";
}
if ($filter['keyword']) {
$where[] = "subject like '%" . addslashes($filter['keyword']) . "%'";
}
if ($filter['del_status']) {
$where[] = 'del_status =\'' . intval($filter['del_status']) . '\'';
}
if ($filter['is_sec']) {
$where[] = "is_sec ='" . $filter['is_sec'] . "'";
}
if ($filter['to_id']) {
$where[] = "(to_id ='" . $filter['to_id'] . "' or to_id = 0)";
}
if ($filter['to_type']) {
$where[] = "to_type ='" . $filter['to_type'] . "'";
}
if ($filter['unread']) {
$where[] = "unread ='" . $filter['unread'] . "'";
}
unset($filter['keyword']);
return parent::_filter($filter) . ' AND ' . implode($where, ' AND ');
}
