function abrirPag(valor){
	var url = valor;

	xmlRequest.onreadystatechange = mudancaEstado;
	xmlRequest.open("GET",url,true);
	xmlRequest.send(null);

		if (xmlRequest.readyState == 1) {
			document.getElementById("conteudo").innerHTML = "<img src='images/loading.gif'>";
		}

	return url;
}

function mudancaEstado(){
	if (xmlRequest.readyState == 4){
		document.getElementById("conteudo").innerHTML = xmlRequest.responseText;
	}
}