declare
v_id number := 1;
v_name varchar2(30);
v_counter number := 0;
begin
loop
select country_name into v_name from wf_countries
where country_id = v_id ;
v_id := v_counter + 1;
exit when v_counter > 3;
end loop;
dbms_output.put_line (v_name);
end; 

this is the correct code

declare
v_name varchar2(30);
v_counter number := 1;
begin
loop
select country_name into v_name from wf_countries
where country_id = v_counter ;
dbms_output.put_line (v_name);
v_counter := v_counter + 1;
exit when v_counter > 3;
end loop;

end;

Best regards,

Eng. Saeed H. Keshk
System Analyst - Riyadh Municipality
Mobile KSA : (+966 54) 023-3171
Mobile EGYPT : (+2 012) 426-6883

شكرا