How to create a table with reference key

[admin]

Dear Freiends!!

I am trying to create a table with reference key in postgresql as below.
table1: create table ta1(sno int, name varchar(20),id int primary key);
table created...
table2:
create table ta2(id int references ta1(id), area varchar(20));
i get an error as:
"NOTICE: CREATE TABLE / FOREIGN KEY clause ignored; not yet implemented.
CREATE."

My table2 has been created but not with a reference key...
Can any one help to sort this problem..
Thank Q In Advance,

Santu.