How to Unregister from the IM Gateway?

Hi All,

I registered on the IM gateway for a service viz . yahoo, Gtalk. Now i want to unregister the user.

I tried following :::::::

<iq type=‘set’

from=‘romeo@montague.lit/orchard’

to=‘aim.shakespeare.lit’

id=‘unreg1’>

<query xmlns=‘jabber:iq:register’>

<remove/>

</query>

</iq>

but i am not getting any kind of response from the server.

If some one can help in that.

Thanks in advance.