function FactoryXMLHttpRequest() {

	if( window.XMLHttpRequest ) {
		return new XMLHttpRequest();
	}
	else if( window.ActiveXObject ) {
		var msxmls = new Array(
			'Msxml2.XMLHTTP.5.0',
			'Msxml2.XMLHTTP.4.0',
			'Msxml2.XMLHTTP.3.0',
			'Msxml2.XMLHTTP',
			'Microsoft.XMLHTTP' );
		for( var i = 0; i < msxmls.length; i++ ) {
			try {
				return new ActiveXObject( msxmls[i] );
			} catch( e ) {}
		}
	}
	throw new Error( "Could not instantiate XMLHttpRequest" );
}

function Asynchronous() {
	this._xmlhttp = new FactoryXMLHttpRequest();
}

function Asynchronous_call( url ) {
	var instance = this;
	this._xmlhttp.abort();
	this._xmlhttp.open('GET', url, true );
	this._xmlhttp.onreadystatechange = function() {
		try {
			switch( instance._xmlhttp.readyState ) {
				case 1:
					instance.loading();
					break;
				case 2:
					instance.loaded();
					break;
				case 3:
					instance.interactive();
					break;
				case 4:
					instance.complete( instance._xmlhttp.status, 
						instance._xmlhttp.statusText, 
						instance._xmlhttp.responseText,
						instance._xmlhttp.responseXML );
					break;
			}
		} catch( e ) {}
	}
	try {
		this._xmlhttp.send( null );
	}catch(e) {}
}
function Asynchronous_loading() {
}

function Asynchronous_loaded() {
}

function Asynchronous_interactive() {
}

function Asynchronous_complete( status, statusText, responseText, responseXML ) {
}

Asynchronous.prototype.loading = Asynchronous_loading;
Asynchronous.prototype.loaded = Asynchronous_loaded
Asynchronous.prototype.interactive = Asynchronous_interactive;
Asynchronous.prototype.complete = Asynchronous_complete;

Asynchronous.prototype.call = Asynchronous_call;