function updatePage() {
  if (request.readyState == 4) {
    if (request.status == 200) {
      /* Get the response from the server */
      var response = request.responseText;
      var alert = response.substring(0, 1);
      var alertText = response.substring(2, response.length);
    if (alert == "1") {
      window.location = "done.php";
    } else {
      var currentAlert = 
      document.getElementById("alert").innerHTML = alertText;
      document.getElementById("continue").disabled=false;
      var currentStatus = 
      document.getElementById("status");
      replaceText(currentStatus, "(( see error above ))");
    }
    } else {
      alert("Error! Request status is " + request.status);
    }
   }
}

function processForm() {
  document.getElementById("continue").disabled=true;
  var currentStatus = 
      document.getElementById("status");
      replaceText(currentStatus, "(( working...please wait ))");
  var friendE = document.getElementById("friend_email").value;
  var yourE = document.getElementById("your_email").value;
  var comments = document.getElementById("comments").value;
  var yourN = document.getElementById("your_name").value;
  var code = document.getElementById("code").value;
  var url = "process_tell_a_friend.php";
  request.open("POST", url, true);
  request.onreadystatechange = updatePage;
  request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
  request.send("friend_email=" + escape(friendE) + "&your_email=" + escape(yourE) + "&comments=" + escape(comments) + "&your_name=" + escape(yourN) + "&code=" + escape(code));
}