ORACLE 10G:Get a column in a single comma separated string

The following code I found was quite helpfule to me.This gives you a single column values in comma separated form.
SELECT
LTRIM( REPLACE(
REPLACE(
XMLAGG(XMLELEMENT("x", clientid) ORDER BY clientid),
'',
','
),
''
),','
) as allclients

FROM (SELECT DISTINCT clientid
FROM clients)

In above query there is a table called clients where clientid is a field.
When above query is executed the result will be as shown below:

clients
1,2,3,4,5,.....


where the client with ids 1-5 are present in the clients table.
This worked perfectly in oracle 10g. I haven't checked in other.