Selecting from table into an array var

Hi,

I'm trying to write a very simple function statement to select a
single integer field from a table and save it into an int array. For
some reason I can't seem to find the correct syntax:

CREATE TABLE sample (
id integer
);

and then within a function:

my_array int[];
my_array = SELECT ARRAY(id) FROM sample;

This syntax and variations of it don't work. Can anyone show me the
correct approach?