try{
	xmlhttp=new XMLHttpRequest()
}catch(e){
	try{
		xmlhttp=new ActiveXObject("MSXML2.XMLHTTP")
	}catch(E){
		try{
			xmlhttp=new ActiveXObject("Microsoft.XMLHTTP")
		}catch(e){
			xmlhttp=false
		}
	}
}

ajax_Fila=[]
ajax_retHTML=[]
ajax_FilaJson=[]
ajax_carregando="<span class='carregando'>Aguarde, carregando...</span>"

function ret_doRequest(){
	if(xmlhttp.readyState==4){
		ajax_Fila[0][1](xmlhttp.responseText)
		ajax_Fila.shift()
		if(ajax_Fila.length>0)real_doRequest()
	}
}

function doRequest(url,fn,dados){
	ajax_Fila.push([url,fn,dados])
	if(ajax_Fila.length==1)real_doRequest()
}

function real_doRequest(){
	url=ajax_Fila[0][0]
	fn=ajax_Fila[0][1]
	dados=ajax_Fila[0][2]
	ajax_retFunc=fn
	method=typeof dados=="undefined"?"GET":"POST"
	xmlhttp.open(
		method,
		url+(url.indexOf("?")==-1?"?":"&")+Math.random(),
		true
	)
	xmlhttp.onreadystatechange=ret_doRequest
	if(method=="POST"){
		xmlhttp.setRequestHeader("Content-type","application/x-www-form-urlencoded")
	}
	dados=typeof dados=="undefined"?null:dados
	if(dados!=null && typeof dados!="string"){
		if(dados.nodeType){
			dados=encodeForm(dados)
		}else{
			dados=encodeURI(dados)
		}
	}
	xmlhttp.send(dados)
}

function ret_doHTML(t){
	ajax_retHTML.shift().innerHTML=t
}

function doHTML(url,o,dados){
	ajax_retHTML.push(o)
	ajax_retHTML.innerHTML=ajax_carregando
	doRequest(url,ret_doHTML,dados)
}

function ret_doJSON(t){
	var f=ajax_FilaJson.shift()
	f(eval("["+t+"]")[0])
}

function doJSON(url,f,dados){
	ajax_FilaJson.push(f)
	doRequest(url,ret_doJSON,dados)
}

function encodeURI(d){
	t=""
	for(i in d)
		t+=encodeURIComponent(i)+"="+
		   encodeURIComponent(d[i])+"&"
	return t
}

function encodeForm(f){
	var o={}
	for(var i=0;i<f.elements.length;i++)
		if(f[i].name!="")o[f[i].name]=f[i].value
	return encodeURI(o)
}