// Returns the content of a text file from its location

function queryTextFile(url) {
	var req = createRequestObject();
	req.open("GET", url);
	return req;
}

// Creates a new instance of an XMLHttpRequest object

function createRequestObject() {
	var XMLHttpRequestObject;
	var browser = navigator.appName;

	if(browser == "Microsoft Internet Explorer"){
		XMLHttpRequestObject = new ActiveXObject("Microsoft.XMLHTTP");
	} else {
		XMLHttpRequestObject = new XMLHttpRequest();
	}

	return XMLHttpRequestObject;
}

function changeElementContent(elementToReplace,URI) {
	var req = queryTextFile(URI);

	req.onreadystatechange = function() {
		if(req.readyState == 4) {
			var responseStr = getResponseData(req);
			var element=document.getElementById(elementToReplace);
	
			if (element!=null) element.innerHTML=responseStr;
		}
	}

	req.send(null);
}

function getResponseData(request) {
	var requestComplete = 4; //denotes a successful request was made
	var requestInteractive = 3; //Commincation is occuring
	var requestLoaded = 2; //information has been loaded
	var requestLoading = 1; //information is loading
	var requestSuccessful = 200; //denotes that the request page was found

	if(request.readyState == requestComplete) {
		if(request.status == requestSuccessful) {
			return request.responseText;
		} else {
			return -1;
		}
	} else {
		return 0;
	}
}