The XMLHttpRequest object provides client-side protocol support for communication with HTTP servers. A client computer can use the XMLHttpRequest object (Microsoft.XMLHTTP) to send an HTTP request, to receive the response, and to have the Microsoft XML Document Object Model (XML DOM) parse that response.
This object is integrated with Microsoft's XML to support sending the request body directly from, and parsing the response directly into, the Microsoft XML DOM objects. This object allows us to post XML from a client application to an ASP page.
Here is a client-side JScript code that shows how we can use this object. In this example, we initialize a request with the open method, specifying the HTTP method to use and the URL to connect to. We then use the send method to send the contents of the XML data island to the designated URL.
objXmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
objXmlHttp.open("POST", "SampleAspPage.asp", false);