Oracle Text url_Datastore error

[sachi2001]

Hi,

I am working with Intermedia Text in Oracle 8.7.3.

I am trying to index a column having URL's,using proxy server to connect to internet.

I create a preference.
ctx_ddl.create_preference('url_pref','URL_DATASTORE')

Since I need to use Proxy server,
ctx_ddl.set_attribute('url_pref','HTTP_PROXY',<name of the proxy server>)

CREATE INDEX DOC_test ON DOC(URL)
indextype IS ctxsys.context parameters ( 'Datastore url_pref' )

But I get the following error.

Unknown HTTP Exception accessing <url>

Can anyone help?