/*
 * Returns an new XMLHttpRequest object, or false if the browser
 * doesn't support it
 */
function newXMLHttpRequest() {

	var xmlreq = false;

	// Create XMLHttpRequest object in non-Microsoft browsers
	if (window.XMLHttpRequest) {
		xmlreq = new XMLHttpRequest();
	} else if (window.ActiveXObject) {
		try {
			// Try to create XMLHttpRequest in later versions
			// of Internet Explorer
			xmlreq = new ActiveXObject("Msxml2.XMLHTTP");
		} 
		catch (e1) {
			// Failed to create required ActiveXObject
			try {
				// Try version supported by older versions
				// of Internet Explorer
				xmlreq = new ActiveXObject("Microsoft.XMLHTTP");
			}
			catch (e2) {
				// Unable to create an XMLHttpRequest by any means
				xmlreq = false;
			}
		}
	}
	return xmlreq;
}

/*
* Returns a function that waits for the specified XMLHttpRequest
* to complete, then passes it XML response to the given handler function.
* req - The XMLHttpRequest whose state is changing
* responseXmlHandler - Function to pass the XML response to
*/
function getReadyStateHandlerForXML(req, responseXmlHandler) {
	// Return an anonymous function that listens to the XMLHttpRequest instance
	return function () {
		// If the request's status is "complete"
		if (req.readyState == 4) {
			// Check that we received a successful response from the server
			if (req.status == 200) {
				// Pass the XML payload of the response to the handler function.
				responseXmlHandler(req.responseXML);
			} 
			else {
				// An HTTP problem has occurred
			}
		}
	}
 }
 
 
 function getReadyStateHandlerForText(req, responseTextHandler) {
	// Return an anonymous function that listens to the XMLHttpRequest instance
	return function () {
		// If the request's status is "complete"
		if (req.readyState == 4) {
			// Check that we received a successful response from the server
			if (req.status == 200) {
				// Pass the XML payload of the response to the handler function.
				responseTextHandler(req.responseText);
			} 
			else {
				// An HTTP problem has occurred
			}
		}
	}
 }