Adding "on delete cascade" after table creation ?

Hi there,

i have a table that SHOULD look like this:

create table lr_object_usage (
lr_object_usage_id integer
constraint
lr_object_usage_lr_object_usage_id_pk
primary key,
lr_object_id integer
constraint lr_object_usage_lr_object_id_fk
references lr_objects(lr_object_id)
on delete cascade,
access_time timestamp,
user_id integer
constraint lr_object_usage_user_id_fk
references users(user_id),
status varchar(11),
context integer
constraint lr_object_usage_context_fk
references
lr_object_usage(lr_object_usage_id)
___ON DELETE CASCADE___
);

unfortunately i think that the table was created without the delete
cascade in the last line (for the constraint
lr_object_usage_context_fk). Is it somehow possible to add the delete
cascade without recreating the table?

TIA, peter