SQL & PL/SQL :: Declaring Global Variable Inside Package?

I want to declare global variable inside package. get the correct query. how to assign value for that variable.

SQL> create or replace
2 PACKAGE new_pack
3 AS
4 g_id employee_details1.employee_id%type;
5 PROCEDURE emp_project(
6 st_date IN DATE,
7 Prj_id out VARCHAR2,
8 prj_name out VARCHAR2,
9 Prj_location out VARCHAR2);
10
11 END new_pack;
12 /

Package created.

SQL> CREATE OR REPLACE
2 PACKAGE body new_pack
3 AS
4 PROCEDURE emp_project(
5 st_date IN DATE,
6 Prj_id OUT VARCHAR2,
7 prj_name OUT VARCHAR2,
8 Prj_location OUT VARCHAR2)

[Code] ..........

Warning: Package Body created with compilation errors.

SQL> show error
Errors for PACKAGE BODY NEW_PACK:

LINE/COL ERROR
-------- -----------------------------------------------------------------
12/12 PLS-00103: Encountered the symbol "=" when expecting one of the
following:
constant exception
table LONG_ double ref
char time timestamp interval date binary national character
nchar