foreign keys as arrays

Is there a way I can do something like the following?

create table t1 (
t1id serial,
);

create table t2 (
t1id int[] references t1 (t1id)
);

I know this doesn't work because I get an error message when trying to
insert into t2.

I'd like to be able allow multiple references if possible.  Has anyone found
a way to make this work?

Also, how do I update an array field?

For example, t2.t1id = '{1,2,3}' and I want to add 4 to make it t2.t1id =
'{1,2,3,4}'.

Thanks.
Alan Young
Programmer/Analyst
IDIGlobal.com