function update() {
  if (request.readyState == 4) {
    if (request.status == 200) {
      /* Get the response from the server */
      var response = request.responseText;
      var array = response.split("|");
      var alertNumber = array[0];
      var alertText = array[1];
      if (alertNumber == "1") {
      window.location = alertText;
      } else if (alertNumber == "2") {
      alert(alertText);
      document.getElementById("continue").disabled=false;
      } else {
      var required = array[2].split("~");
      for (i=0; i < required.length; i++) {
      var name = required[i]+"_label";
      document.getElementById(name).className="label_red";
      }
      alert(alertText);
      document.getElementById("continue").disabled=false;
      }
     } else {
      alert("Error! Request status is " + request.status);
    }
  }
}

function process() {
   document.getElementById("continue").disabled=true;
   var subject = document.getElementById("subject").value;
   var question_1 = getradio("question_1");
   var question_2 = getradio("question_2");
   var question_3 = getradio("question_3");
   var question_4 = getradio("question_4");
   var question_5 = getradio("question_5");
   var question_6 = getradio("question_6");
   var question_7 = getradio("question_7");
   var question_8 = getradio("question_8");
   var question_9 = getradio("question_9");
   var question_10 = getradio("question_10");
   var question_11 = getradio("question_11");
   var question_12 = getradio("question_12");
   var question_13 = getradio("question_13");
   var question_14 = getradio("question_14");
   var question_15 = getradio("question_15");
   var question_16 = getradio("question_16");
   var question_17 = getradio("question_17");
   var question_18 = getradio("question_18");
   var question_19 = getradio("question_19");
   var question_20 = getradio("question_20");
   var question_21 = getradio("question_21");
   var question_22 = getradio("question_22");
   var comments2 = document.getElementById("comments2").value;
   var url = "survey_do.php";
   request.open("POST", url, true);
   request.onreadystatechange = update;
   request.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
   request.send("subject=" + escape(subject) + "&question_1=" + escape(question_1) + "&question_2=" + escape(question_2) + "&question_3=" + escape(question_3) + "&question_4=" + escape(question_4) + "&question_5=" + escape(question_5) + "&question_6=" + escape(question_6) + "&question_7=" + escape(question_7) + "&question_8=" + escape(question_8) + "&question_9=" + escape(question_9) + "&question_10=" + escape(question_10) + "&question_11=" + escape(question_11) + "&question_12=" + escape(question_12) + "&question_13=" + escape(question_13) + "&question_14=" + escape(question_14) + "&question_15=" + escape(question_15) + "&question_16=" + escape(question_16) + "&question_17=" + escape(question_17) + "&question_18=" + escape(question_18) + "&question_19=" + escape(question_19) + "&question_20=" + escape(question_20) + "&question_21=" + escape(question_21) + "&question_22=" + escape(question_22) + "&comments2=" + escape(comments2));        
}

function getradio(name) {
  var group = document.getElementsByName(name);
  for (i=0; i < group.length; i++) {
    if (group[i].checked == true) {
      var radiovalue = group[i].value;
    }
  }
  if (radiovalue == undefined) {
  return "";
  } else {
  return radiovalue;
  }
}