Problem on Geometric functions

Hello,

I have a table that has an attribute 'identifier', declared as integer
and an attribute 'plane_coord' defined as 'point':

Table "reference.coord_test"   Column    |  Type   | Modifiers
-------------+---------+----------- node_name   | integer | plane_coord | point   |


I would like to find all points from the table that are within a square.
Is this possible to do so? I have just found a check-operator to find
out if a specified point is contained in or on a figure:
point '(1,1)' @ box '((0,0),(2,2))'
(on http://www.postgresql.org/docs/7.4/interactive/functions-geometry.html).

I am looking for something like

SELECT point(x,y)
FROM reference.coord_test
WHERE point(x,y) € box '((0,0), (2,2))';

Has anyone experience with that?

Regards,

Silke

By the way, I am using PostGreSQL 7.4.1