Package employee is 
  procedure add_emp(P_ename IN varchar2
                   ,P_job   IN varchar2
                   ,P_sal   IN number
                   );
  procedure del_emp(P_empid IN number);
end;


PACKAGE BODY employee IS

  procedure add_emp(P_ename IN varchar2
                   ,P_job   IN varchar2
                   ,P_sal   IN number
                   )
  IS 
    new_empno number;
  BEGIN

    select emp_no_seq.nextval into new_empno from dual;

    insert into emp(empno,ename,job,sal,hiredate)
    values(new_empno,P_ename,P_job,P_sal,sysdate);
  when no_data_found then  -- or when others...
    -- message or just null;
  END;

  procedure del_emp(P_empid IN number)
  is
  begin
    delete from emp where empno=P_empid;
  end del_emp;

end employee;