function addNews( valor ) {
  http.open("GET", "ajax/addNews.php?email=" + valor, true);
  http.onreadystatechange = handleHttpResponseAddNews;
  x = document.getElementById("ri_mensagem");
  x.innerHTML = "<img src='img/layout/aguarde.gif' />";
  x.style.visibility = "visible";
  http.send(null);
}

function handleHttpResponseAddNews() {

  campo_text = document.getElementById("ri_mensagem");

  if (http.readyState == 4) {
//    campo_select.options.length = 0;

    campo_text.innerHTML = http.responseText;
    
  }

}