Inserting BLOB

Hi all,
I am using following query to create new type 'lo'
create type lo
(internallength=4,externallength=10,input=int4in,output=int4out,
default='',passedbyvalue);

i am trying to insert the image by following query:
insert into table (user_id,image) values
('som',lo_import('/u/grms/Import/XYZ.jpg'));

Here lo_import is used for oid but above type is 'lo' .
It is saying to cast the expression .

Tried by following query also.
insert into table (user_id,image) values ('som','XYZ.jpg');

But it is throwing pg_attoi error : can't parse ' XYZ.jpg'

Could anybody reply earliest with proper queries to insert, update and
delete an image from database.(Postgresql 7.0.0)
(with the help of lo type only)

thanks in advance,
som