function getDomDocumentPrefix() {
	if (getDomDocumentPrefix.prefix)
		return getDomDocumentPrefix.prefix;

	var prefixes = ["MSXML2", "Microsoft", "MSXML", "MSXML3"];
	var o;
	for (var i = 0; i < prefixes.length; i++) {
		try {
			// try to create the objects
			o = new ActiveXObject(prefixes[i] + ".DomDocument");
			return getDomDocumentPrefix.prefix = prefixes[i];
		}
		catch (ex) {};
	}

	throw new Error("Could not find an installed XML parser");
}

function getXmlHttpPrefix() {
	if (getXmlHttpPrefix.prefix)
		return getXmlHttpPrefix.prefix;

	var prefixes = ["MSXML2", "Microsoft", "MSXML", "MSXML3"];
	var o;
	for (var i = 0; i < prefixes.length; i++) {
		try {
			// try to create the objects
			o = new ActiveXObject(prefixes[i] + ".XmlHttp");
			return getXmlHttpPrefix.prefix = prefixes[i];
		}
		catch (ex) {};
	}

	throw new Error("Could not find an installed XMLHttp object");
}

function XmlHttp() {}

XmlHttp.httpPool = [];
XmlHttp.httpMaxSize = 3;

XmlHttp.poolGetHttp = function() {
	  if (XmlHttp.httpPool.length > 0) {
	  	  return XmlHttp.httpPool.pop();
	  }
	  return XmlHttp.create();
}

XmlHttp.poolReturnHttp = function(http) {
	  if (XmlHttp.httpPool.size > XmlHttp.httpMaxSize) {
	  	  delete http;
	  }
	  XmlHttp.httpPool.push(http);
}

XmlHttp.create = function () {
	try {
		// NS & MOZ
		if (window.XMLHttpRequest) {
			var req = new XMLHttpRequest();

			// some versions of Moz do not support the readyState property
			// and the onreadystate event so we patch it!
			if (req.readyState == null) {
				req.readyState = 1;
				req.addEventListener("load", function () {
					req.readyState = 4;
					if (typeof req.onreadystatechange == "function")
						req.onreadystatechange();
				}, false);
			}

			return req;
		}
		// IE
		if (window.ActiveXObject) {
			return new ActiveXObject(getXmlHttpPrefix() + ".XmlHttp");
		}
	}
	catch (ex) {}
	// Fail
	throw new Error("Your browser does not support XmlHttp objects");
};

function XmlDocument() {}
XmlDocument.create = function () {
	try {
		if (document.implementation && document.implementation.createDocument) {
			var doc = document.implementation.createDocument("", "", null);
			if (doc.readyState == null) {
				doc.readyState = 1;
				doc.addEventListener("load", function () {
					doc.readyState = 4;
					if (typeof doc.onreadystatechange == "function")
						doc.onreadystatechange();
				}, false);
			}

			return doc;
		}
		if (window.ActiveXObject)
			return new ActiveXObject(getDomDocumentPrefix() + ".DomDocument");
	}
	catch (ex) {}
	throw new Error("Your browser does not support XmlDocument objects");
};

if (window.DOMParser &&
	window.XMLSerializer &&
	window.Node && Node.prototype && Node.prototype.__defineGetter__) {

	Document.prototype.loadXML = function (s) {

		var doc2 = (new DOMParser()).parseFromString(s, "text/xml");

		while (this.hasChildNodes())
			this.removeChild(this.lastChild);
		for (var i = 0; i < doc2.childNodes.length; i++) {
			this.appendChild(this.importNode(doc2.childNodes[i], true));
		}
	};

	Document.prototype.__defineGetter__("xml", function () {
		return (new XMLSerializer()).serializeToString(this);
	});
}

/*
 * xmlHttp Pool
 *
 * userage: var xmlhttpObj = XmlHttpPool.pick()
 */
var XmlHttpPoolArr = new Array();
var XmlHttpPoolSize = 100;
var XHPCurrentAvailableID = 0;

function XmlHttpPool() {}
XmlHttpPool.pick = function() {
	var pos = XHPCurrentAvailableID;
	XmlHttpPoolArr[pos] =  XmlHttp.create();

	XHPCurrentAvailableID >= (XmlHttpPoolSize-1) ? 0 : XHPCurrentAvailableID++

	return XmlHttpPoolArr[pos];
}

function rpcCall(url, method, data, callback, asyn) {
    var xmlhttp = XmlHttp.create();
	xmlhttp.open(method, url, asyn);
	xmlhttp.send(data);
	if (!asyn) { // if not asyn
		callback(xmlhttp.responseText);
	} else {
		xmlhttp.onreadystatechange = function() {
			if (xmlhttp.readyState == 4) {
				callback(xmlhttp.responseText);
			}
		}
	}
}