Tigger code not working properly in Oracle 11G

Trigger created with compilation error on select object_name ,user into name,p_us from user_objects where object_type='TABLE';

create table track_cr_dr
(
userid varchar(20),
ob_name varchar(50),
action varchar(8),
ac_time varchar(50),
ac_date date 
);

create or replace trigger track_create 
after create or drop on DATABASE
declare
	ac varchar(8);
	name varchar(50);
	p_date date;
	p_time varchar(50);
	p_us varchar(20);
begin
	select sysdate into p_date from dual;
	select to_char(sysdate,'HH:MM:SS') into p_time from dual;
	select object_name ,user into name,p_us from user_objects where object_type='TABLE'; 
	
	if 'creating' then
            ac:='CREATE';
	else
            ac:='DROP';
	end if;
	
	insert into track_cr_dr values(p_us,name,ac,p_time,p_date);
end;