open phpMyadmin
open dolphin DB
open sys_injection
click sql and run this query
INSERT INTO `sys_injections` (`name`, `page_index`, `key`, `type`, `data`, `replace`, `active`) VALUES
('header_login', '0', 'injection_logo_after', 'php', 'replace me', '0', '1')
now edit the created row "name = header_login" and replace data field with below code replacing "replace me"
if (!isMember()) {
echo '';
}
now hit "Go" and clear the cache and you can customize its code as per your need. simple...:)