The selection box on this page calls up a server side program
(an application server / content provider / web service) and
displays elements of the result in the changeable area of the page
This text initially loaded with page
When you make a selection, the answer comes here
Using Ajax, a suitable browser can ask a server for dynamic information
to be filled in to an existing page, without the need to retransmit the
whole page - and in this example, we're calling up a server to replace the
text in the light blue box just above whenever a selection element on the
form is completed.
to the make / version of the browser, so if it's used with a non
compliant browser it will fail silently.