Foreign key did not update with primary key in oracle -

i'm using oracle 11g r2 express edition , sql command line. i'm getting problem when update primary key foreign key did not update. there solution?

this command 2 table

create table staff(staff_id number(5) not null primary key);  create table customer(customer_id number(5) not null primary key,staff_id number(5) not null references staff); 

what did do? sql statement?

did updated primary key value consistent row in customer table? sure there corresponding row in customer table?