// stores the reference to the XMLHttpRequest object
var xmlHttp = createXmlHttpRequestObject();
// holds the remote server address
var serverAddress = "increment";
//var serverAddress;
var serverAddressToSend;
// retrieves the XMLHttpRequest object
function createXmlHttpRequestObject()
{
  // will store the reference to the XMLHttpRequest object
  var xmlHttp;
  // if running Internet Explorer
  if(window.ActiveXObject)
  {
    try
    {
      xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
    }
    catch (e)
    {
      xmlHttp = false;
    }
  }
  // if running Mozilla or other browsers
  else
  {
    try
    {
      xmlHttp = new XMLHttpRequest();
    }
    catch (e)
    {
      xmlHttp = false;
    }
  }
  //**************************
  if(window.ActiveXObject)
  {
    try
    {
      xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
    }
    catch (e)
    {
      xmlHttp = false;
    }
  }
  // if running Mozilla or other browsers
  else
  {
    try
    {
      xmlHttp = new XMLHttpRequest();
    }
    catch (e)
    {
      xmlHttp = false;
    }
  }
  // return the created object or display an error message
  if (!xmlHttp)

    alert("Error creating the XMLHttpRequest object.");
  else
    return xmlHttp;
}

// make asynchronous HTTP request using the XMLHttpRequest object
function increment(type)
{
  serverAddressToSend = serverAddress + "?id=" + type;
  validate();
  return true;

}


function validate()
{

      // proceed only if the xmlHttp object isn't busy
      if (xmlHttp.readyState == 4 || xmlHttp.readyState == 0)
      {
        // execute the quickstart.php page from the server
        xmlHttp.open("GET", serverAddressToSend, true);
        // define the method to handle server responses
        xmlHttp.onreadystatechange = handleServerResponse;
        // make the server request
        xmlHttp.send(null);
      }
      else
        // if the connection is busy, try again after one second
        setTimeout('validate()', 1000);
}

// executed automatically when a message is received from the server
function handleServerResponse()
{
	var qty;
	var field;
  // move forward only if the transaction has completed
  if (xmlHttp.readyState == 4)
  {
    // status of 200 indicates the transaction completed successfully
    if (xmlHttp.status == 200)
    {
      // extract the XML retrieved from the server
      xmlResponse = xmlHttp.responseXML;
      // obtain the document element (the root element) of the XML structure
      xmlDocumentElement = xmlResponse.documentElement;
      // get the text message, which is in the first child of
      // the the document element
      //error = xmlDocumentElement.getElementsByTagName("error")[0].firstChild.data;
      //if (error == 0) {
      //	alert('done');
      //	//document.getElementById("surveyQuestions").style.display = 'none';
      //	//document.getElementById("surveyResults").style.display = '';
      //	//totalQuestions = xmlDocumentElement.getElementsByTagName("totalQuestions")[0].firstChild.data;
      //	//for(i=0; i < totalQuestions; i++)
      //  //{
      //  //	totalAnswers = xmlDocumentElement.getElementsByTagName("totalAnswers"+i)[0].firstChild.data;
      //  //	for(j=0; j < totalAnswers; j++)
      //  //  {
      //  //  	answer = xmlDocumentElement.getElementsByTagName("answer"+i+j)[0].firstChild.data;
      //  //  	document.getElementById('answer'+i+j).innerHTML = answer;
      //  //  }
      //  //}
      //}
      //else {
      //	alert('no done');
      //	//document.getElementById("surveyQuestions").style.display = '';
      //	//document.getElementById("surveyResults").style.display = 'none';
      //}
    }
    // a HTTP status different than 200 signals an error
    else
    {
      alert("There was a problem accessing the server: " + xmlHttp.statusText);
    }
  }
}