Ajax Hacks: Detect Browser Compatibility With the Request Object

Overview

Browser compatibility is an important consideration. One has to make sure the "Engine" behind Ajax's server handshake is properly constructed, but one can never predict which browsers the users will favor. The programming tool that allows Ajax applications to make HTTP requests to a server is an object that you can use from within JavaScript code. In the world of Firefox and Netscape (as well as Safari and Opera), this object is named XMLHttpRequest. However, continuing with the tradition established by IE 5.0, recent vintages of Internet Explorer implement the software as an ActiveX object named Microsoft.XMLHTTP or Msxml2. XMLHTTP.