still having problems

i tried this but i get the following error: create or replace procedure(a_cust_id varchar2, new_address varchar2)
*
ERROR at line 1:
ORA-04050: invalid or missing procedure, function, or package name

create or replace procedure(a_cust_id varchar2, new_address varchar2)
is
begin
update customer
set address=new_address
where id= a_cust_id;
exception
when others then
null;
end;

You have to specify the name for this:

create or replace procedure NAME (p1 in number ...

set serveroutput on
create or replace procedure change_address
(cust_id IN customer.customer_id%TYPE,
cust_id IN varchar2)
RETURN varchar2 IS
new_address varchar2;
begin
update customer
set address=new_address
where id=cust_id;
exception
when others then
null;
end;