function mostrarConteudo(toLoad){
var div = document.getElementById("conteudo");
div.innerHTML = "<center><div style='width: 558px; height: 303px'><br><img src='img/gif/ajax-loader.gif'/><br><br>Aguarde... </div></center>";
var ajax = new Ajax();
ajax.set_receive_handler(
function(c) {
div.innerHTML = c;
}
);
ajax.send(toLoad);
}