If you manage different websites, it is possible to use a single IM / Jabber account to serve all your websites. This means, you just need to login to only 1 jabber account, and all the chat request originated in any of your websites, will point to that single IM account
On the agent settings, select the JABBER ID of another FrescoChat account.
That's all you need. All the chat request for the current FrescoChat account will be redirected to the IM account you selected.