XSS/AJAX question - how do I send data?

[eluser]taewoo[/eluser]
I'm writing an app using CodeIgniter and jQuery. It's an embeddable widget that can be embedded onto 3rd party sites.

Say XYZ.com has my widget, which resides on MY-server.com. XYZ.com has a page which has this..

Code:

script language="javascript" src="http://www.my-site.com/script.js"

(Sorry for weird syntax... codeigniter forum protection i guess)


Now, i've noiced that XYZ.com can PULL information from my-server.com, but cannot send info back. I'm guessing this has to do with XSS security. But i need to send data back to my server.

Does anyone know how this is resolved? I'm sure this is a solved issue b/c Google/yahoo/msn map has already solved this...