I had a look at the http://gmail.com [1] technique for reading data from the client without refreshing the page. I am using this for a long time with the ActiveX Microsoft.XMLHTTP or Microsoft.XMLDOM. But using frames and simple arrays pages are working in Internet Explorer, Firefox, Mozilla,... very cool! A simple page can be viewed at http://demo.pctopp.com/incidents.aspx [2]. If you click on a group (there a machine codes for conversion machines) you can see all the incidents for this group. In the background a page is loaded into a frame: http://demo.pctopp.com/incidents.aspx?cmd=showincidents&groupid=1 [3] If you have a look to the source code you can see on how the new values are put to the parent (main) page.
The same way is used by google on the suggest search: http://www.google.com/webhp?complete=1&hl=en [4] check the http://www.google.com/ac.js [5] funtion to see how they have done the job.