/**
 * ----------------------------------------------------------------------------
 * Copyright (c) 2009 by Hansadigit
 * Hamburg, Germany
 * ----------------------------------------------------------------------------
 * Original Author of file: Oliver Oestrup <info@hansadigit.de>
 * ----------------------------------------------------------------------------
 **/

function Ajax() {
	this.xmlHttp = this.getXMLHttpRequest();
}

Ajax.prototype.getXMLHttpRequest = function() {
	var xmlHttp = false;
	if(typeof XMLHttpRequest != 'undefined') {
		xmlHttp = new XMLHttpRequest();
	}
	else {
		try {
			xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
		}
		catch(e) {
			try {
				xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
			}
			catch(e) {
				xmlHttp = false;
			}
		}
	}
	if(!xmlHttp) {
		alert("Cannot create XMLHTTP instance");
	}
	return xmlHttp;
}

Ajax.prototype.request = function(url, parameters, method) {
	
	if(typeof url == "undefined" || url == "") {
		url = location.href;
	}
	
	url = url.replace(/#.*$/, "");
	
	if(typeof parameters == "undefined") {
		parameters = [];
	}
	
	if(typeof method == "undefined") {
		method = "GET";
	}
	method = method.toUpperCase();
	
	if(!this.xmlHttp) {
		return false;
	}
	
	this.data = "";
	this.error = false;
	
	var parametersStr = "";
	
	for(var x in parameters) {
		if(typeof parameters[x] == "object") {
			for(var y in parameters[x]) {
				addParam(x, parameters[x][y]);
			}
		}
		else {
			addParam(x, parameters[x]);
		}
	}
	
	if(method == "POST") {
		this.xmlHttp.open("POST", url, true);
		this.xmlHttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
		this.xmlHttp.setRequestHeader("Content-length", parametersStr.length);
		this.xmlHttp.setRequestHeader("Connection", "close");
	}
	else {
		this.xmlHttp.open("GET", url + ((parametersStr.length)? ((url.search(/\?/) == -1)? "?" : "&") + parametersStr : ""), true);
	}
	
	var ajax = this;
	
	this.xmlHttp.onreadystatechange = function() {
		if(ajax.xmlHttp.readyState == 4) {
			if(ajax.xmlHttp.status == 200 && ajax.xmlHttp.responseText != "") {
				ajax.data = ajax.xmlHttp.responseText;
			}
			else {
				ajax.data = ajax.xmlHttp.statusText;
				ajax.error = true;
			}
			ajax.response();
		}
	}
	
	if(method == "POST") {
		this.xmlHttp.send(parametersStr);
	}
	else {
		this.xmlHttp.send(null);
	}
	
	function addParam(name, value) {
		parametersStr += (parametersStr.length? "&" : "") + encodeURIComponent(name) + "=" + encodeURIComponent(value);
	}
}

Ajax.prototype.sendForm = function(form) {
	var parameters = [];
	
	for(var x = 0; x < form.elements.length; x++) { // select, radio gesondert behandeln !!!!
		var element = form.elements[x];
		if(typeof parameters[element.name] == "undefined") {
			parameters[element.name] = [];
		}
		parameters[element.name].push(element.value);
	}
	
	this.request(form.action, parameters, form.method);
}

Ajax.prototype.sendLink = function(a) {
	this.request(a.href);
}

Ajax.prototype.response = function() {}