// AJAXutil.js:
//
// This class supports AJAX functionality.
//

     
// AJAXutil:
//
// This is the init method.
//
function AJAXutil()
{
    this.request = new Object();   

} // AJAXutil


// initReq:
//
// Initialize a request object that is already constructed.
//		Parameters:
//			reqType:	The HTTP request type, such as GET or POST.
//			url:		The URL of the server program.
//			isAsynch:	Whether to send the request asynchronously or not.
//
AJAXutil.prototype.initReq = function(reqType, url, callback, isAsync)
{
	// Specify the function that will handle the HTTP response.
	this.request.onreadystatechange = callback;	
	this.request.open(reqType, url, isAsync);
	
	
	// Set the Content-Type header for a POST request
	if(reqType == "POST")
	{
		this.request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
		this.request.send(queryString);
	}
	else
		this.request.send(null); // Not posting anything to the page.
	
} // initReq


// httpRequest:
//
// This creates the XMLHttpRequest object.
//
//	Wrapper function for constructing a request object.
//		Parameters:
//			reqType:	The HTTP request type, such as GET or POST.
//			url:		The URL of the server program.
//			asynch:		Whether to  send the request asynchronously or not.
// 
AJAXutil.prototype.httpRequest = function(reqType, url, callback, async)
{
	// Mozilla-based browsers
	if(window.XMLHttpRequest)
		this.request = new XMLHttpRequest();
	else if(window.ActiveXObject)
	{
		this.request = new ActiveXObject("Msxml2.XMLHTTP");
		if(!this.request)
			this.request = new ActiveXObject("Microsoft.XMLHTTP");
	}
	
	// Initialization succeeded
	if(this.request)
    	this.initReq(reqType, url, callback, async);
	else
		alert("Your browser does not permit the use of all of this application's features!");
	
} // httpRequest