SQL & PL/SQL :: Calling A Function In Package

I have this following pakg

CREATE OR REPLACE PACKAGE pkg_test AS

-- Create a table type of the table you want
TYPE tbl_test IS varray(100) of VARCHAR2(30);

-- Function that will return the table type
FUNCTION fnc_test RETURN tbl_test;

-- End package
END;

CREATE OR REPLACE PACKAGE BODY pkg_test AS
FUNCTION fnc_test RETURN tbl_test IS
-- type table_name_va is varray(100) of VARCHAR2(30);
-- Variable of the type tbl_test

[code]...

But i am having problem calling this to test it.

declare
TYPE tbl_test IS varray(100) of VARCHAR2(30);
var_tbl_test tbl_test;
begin
var_tbl_test:= pkg_test.fnc_test;

[code]...