cross domain load of data

cross domain load of data

I've been getting to grips with jQuery, mostly with PHP, on my own site and loving it, so trying to use it in a new project I am working on.
 
Basically, I have some content loaded onto a clients server and when it launches it gewts the users previous data from my server. So, to get the initial user data, the page on their server makes a jQuery call to my server to get the users previous progress.
 
My problem is that both servers are different domains, and I am getting warnings about the page accessing information beyond it's control. I want to avoid this if at all possible. I had thought that jQuery supported cross domain loading of data so my questions are -
1. Am I correct I can load data from a different domain (without needing to make server modifications on the clients server)?
2. How do I do it - presuming what I have done is wrong (shown below roughly)?
 
Thanks a lot!
Andy
 
  1. <script language="JavaScript" src="../jscripts/jquery-1.4.2.min.js"></script>
    <script language="JavaScript">
  2. var remoteaddress="http://www.xxxxxxx.com";
  3. var userID="abcdefg";
  4. var contentID="item36";
  6. function getusersupdate(){
        callAddress = remoteaddress+"/adminpages/getUsersData.asp?userid="+userID+"&contentID="+contentid;
        $.get(callAddress, updateuserdata);
    }



  7. function updateuserdata(data){
         alert(data);
         //do stuff with the data


  8. }
  9. $(document).ready(getusersupdate);