var Ajaxs = new Array();
var AjaxStacks = new Array(0, 0, 0, 0, 0, 0, 0, 0, 0, 0);


function Ajax(recvType, waitId) {

	for(var stackId = 0; stackId < AjaxStacks.length && AjaxStacks[stackId] != 0; stackId++);
	AjaxStacks[stackId] = 1;

	var aj = new Object();

	aj.loading = 'Loading...';//public
	aj.recvType = recvType ? recvType : 'XML';//public
	aj.waitId = !!waitId ? $E(waitId) : null;//public

	aj.resultHandle = null;//private
	aj.sendString = '';//private
	aj.targetUrl = '';//private
	aj.stackId = 0;
	aj.stackId = stackId;

	aj.setLoading = function(loading) {
		if(typeof loading !== 'undefined' && loading !== null) aj.loading = loading;
	}

	aj.setRecvType = function(recvtype) {
		aj.recvType = recvtype;
	}

	aj.setWaitId = function(waitid) {
		aj.waitId = $E(waitid);
	}

	aj.createXMLHttpRequest = function() {
		var request = false;
		if(window.XMLHttpRequest) {
			request = new XMLHttpRequest();
			if(request.overrideMimeType) {
				request.overrideMimeType('text/xml');
			}
		} else if(window.ActiveXObject) {
			var versions = ['Microsoft.XMLHTTP', 'MSXML.XMLHTTP', 'Microsoft.XMLHTTP', 'Msxml2.XMLHTTP.7.0', 'Msxml2.XMLHTTP.6.0', 'Msxml2.XMLHTTP.5.0', 'Msxml2.XMLHTTP.4.0', 'MSXML2.XMLHTTP.3.0', 'MSXML2.XMLHTTP'];
			for(var i=0; i<versions.length; i++) {
				try {
					request = new ActiveXObject(versions[i]);
					if(request) {
						return request;
					}
				} catch(e) {}
			}
		}
		return request;
	}

	aj.XMLHttpRequest = aj.createXMLHttpRequest();
	aj.showLoading = function() {
		if(aj.waitId && (aj.XMLHttpRequest.readyState != 4 || aj.XMLHttpRequest.status != 200)) {
			changedisplay(aj.waitId, '');
			aj.waitId.innerHTML = '<img src="/Public/Images/loading.gif" align="absmiddle" /> ' + aj.loading + '';
		}
	}

	aj.processHandle = function() {
		if(aj.XMLHttpRequest.readyState == 4 && aj.XMLHttpRequest.status == 200) {
			for(k in Ajaxs) {
				if(Ajaxs[k] == aj.targetUrl) {
					Ajaxs[k] = null;
				}
			}
			if(aj.waitId) changedisplay(aj.waitId, 'hidden');
			if(aj.recvType == 'HTML') {
				aj.resultHandle(aj.XMLHttpRequest.responseText, aj);
			} else if(aj.recvType == 'XML') {
				try {
					aj.resultHandle(aj.XMLHttpRequest.responseXML.lastChild.firstChild.nodeValue, aj);
				} catch(e) {
					aj.resultHandle('', aj);
				}
			}
			AjaxStacks[aj.stackId] = 0;
		}
	}

	aj.get = function(targetUrl, resultHandle) {	
		if(targetUrl.indexOf('?') != -1) {
			targetUrl = targetUrl + '&inajax=1&rnd=' + Math.random();
		} else {
			targetUrl = targetUrl + '?inajax=1&rnd=' + Math.random();
		}
		setTimeout(function(){aj.showLoading()}, 500);
		if(in_array(targetUrl, Ajaxs)) {
			return false;
		} else {
			Ajaxs.push(targetUrl);
		}
		aj.targetUrl = targetUrl;
		aj.XMLHttpRequest.onreadystatechange = aj.processHandle;
		aj.resultHandle = resultHandle;
		var delay = 100;
		if(window.XMLHttpRequest) {
			setTimeout(function(){
			aj.XMLHttpRequest.open('GET', aj.targetUrl);
			aj.XMLHttpRequest.send(null);}, delay);
		} else {
			setTimeout(function(){
			aj.XMLHttpRequest.open("GET", targetUrl, true);
			aj.XMLHttpRequest.send();}, delay);
		}

	}
	aj.post = function(targetUrl, sendString, resultHandle) {
		if(targetUrl.indexOf('?') != -1) {
			targetUrl = targetUrl + '&inajax=1';
		} else {
			targetUrl = targetUrl + '?inajax=1';
		}
		setTimeout(function(){aj.showLoading()}, 500);
		if(in_array(targetUrl, Ajaxs)) {
			return false;
		} else {
			Ajaxs.push(targetUrl);
		}
		aj.targetUrl = targetUrl;
		aj.sendString = sendString;
		aj.XMLHttpRequest.onreadystatechange = aj.processHandle;
		aj.resultHandle = resultHandle;
		aj.XMLHttpRequest.open('POST', targetUrl);
		aj.XMLHttpRequest.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
		aj.XMLHttpRequest.send(aj.sendString);
	}
	return aj;
}

function changedisplay(obj, display) {
	if(display == 'auto') {
		obj.className = obj.className == '' ? 'hidden' : '';
	} else {
		obj.className = display;
	}
	return false;
}



function $E(el){
	if(!el)
	{
		return null;
	}
	else if(typeof el=='string')
	{
		return document.getElementById(el);
	}
	else if(typeof el=='object')
	{
		return el;
	}
}

function in_array(needle, haystack) {
	if(typeof needle == 'string' || typeof needle == 'number') {
		for(var i in haystack) {
			if(haystack[i] == needle) {
					return true;
			}
		}
	}
	return false;
}