function abrirPag(valor){
var url = valor;
xmlRequest.open("GET", url, true);
xmlRequest.onreadystatechange = mudancaEstado;
xmlRequest.send(null);
if (xmlRequest.readyState == 1) {
document.getElementById("conteudo").innerHTML = "<img src='images/loader.gif'>";
}
return url;
}
function mudancaEstado(){
if (xmlRequest.readyState == 4){
document.getElementById("conteudo").innerHTML = xmlRequest.responseText;
}
}