automatic value conversion

Hi,

currently I do this:

INSERT INTO table1 (row1) VALUES ( function_in('argument1','myvalue'))
and
select function_out('argument1',row1) from table1; (which gives
'myvalue' again)

funtion_out(text,int) returns text
funtion_in(text,text) returns int

the table looks like this:

create table table1
(
row1 integer;
)

instead of the select and insert statements above I want to do this:

INSERT INTO table1 (row1) VALUES ( 'myvalue' )
and
select row1 from table1; (which gives 'myvalue' again, but in reality
some integer is stored in the database)

the functions function_in and function_out should be called
automatically on select or insert / update.

How can I change the table definition to use function_in and
function_out transparently for me (as if the table had a text colum)

(remember function_in and function_out convert von int to text and
have an addional fixed text argument)

Thank you very much for your Help !!

Sebastian