Oracle - error en paquete

tengo el siguiente paquete.
create or replace package emp_util
is
FUNCTION avg_sal_nr(p_deptno dept.deptno%type)
return number;
end;

create or replace package body emp_util
-- ES LO MISMO USAR IS O AS AQUI??
as
function avg_sal_nr(p_deptno dept.deptno%type)
return number
is
cursor c_avg_sal_nr(p_dept dept.deptno%type)
is
select avg(sal) avg_sal_nr
from emp
where deptno=p_dept;
v_casr c_avg_sal_nr%rowtype;
v_found boolean;
BEGIN
OPEN c_avg_sal_nr(p_deptno);
FETCH c_avg_sal_nr INTO v_casr;
v_found:=c_avg_sal_nr%found;
close c_avg_sal_nr;
return v_casr;
end avg_sal_nr;
end emp_util;

y me tira error en la línea 18 del body que estoy haciendo mal? En el código del body agregue 1 preguntas.
GRacias

create or replace package body emp_util is
function avg_sal_nr(p_deptno dept.deptno%type)
return number
is
cursor c_avg_sal_nr(p_dept dept.deptno%type)
is
select avg(sal) avg_sal_nr
from emp
where deptno=p_dept;
v_casr number;
v_found boolean;
BEGIN
OPEN c_avg_sal_nr(p_deptno);
FETCH c_avg_sal_nr INTO v_casr;
v_found:=c_avg_sal_nr%found;
close c_avg_sal_nr;
return v_casr;
end avg_sal_nr;
end emp_util;