// stores the reference to the XMLHttpRequest object
var xmlHttp = createXmlHttpRequestObject(); 

// 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;
    }
  }
  // return the created object or display an error message
  if (!xmlHttp)
 
    alert("Error creating the XMLHttpRequest object.");
  else 
    return xmlHttp;
}

function checkfname()
{
  // proceed only if the xmlHttp object isn't busy
  if (xmlHttp.readyState == 4 || xmlHttp.readyState == 0)
  {
	fname = encodeURIComponent(document.getElementById('fname').value);
    // execute the validate.php page from the server
    xmlHttp.open("GET", "inc/php/validate.php?dataType=fname&&validateType=AJAX&&fname=" + fname, 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('checkfname()', 10000);
}
function checklname()
{
  // proceed only if the xmlHttp object isn't busy
  if (xmlHttp.readyState == 4 || xmlHttp.readyState == 0)
  {
	lname = encodeURIComponent(document.getElementById('lname').value);
    // execute the validate.php page from the server
    xmlHttp.open("GET", "inc/php/validate.php?dataType=lname&&validateType=AJAX&&lname=" + lname, 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('checklname()', 1000);
}

// make asynchronous HTTP request using the XMLHttpRequest object 
function checkemail()
{
  // proceed only if the xmlHttp object isn't busy
  if (xmlHttp.readyState == 4 || xmlHttp.readyState == 0)
  {
    // retrieve the name typed by the user on the form
    email = encodeURIComponent(document.getElementById('email').value);
    // execute the quickstart.php page from the server
    xmlHttp.open("GET", "inc/php/validate.php?dataType=email&&email=" + email + "&&validateType=AJAX", 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('checkemail()', 1000);
}
function checksubject()
{
  // proceed only if the xmlHttp object isn't busy
  if (xmlHttp.readyState == 4 || xmlHttp.readyState == 0)
  {
    // retrieve the name typed by the user on the form
    subject = encodeURIComponent(document.getElementById('subject').value);
    // execute the quickstart.php page from the server
    xmlHttp.open("GET", "inc/php/validate.php?dataType=subject&&subject=" + subject + "&&validateType=AJAX", 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('checksubject()', 1000);
}
function checkmessage()
{
  // proceed only if the xmlHttp object isn't busy
  if (xmlHttp.readyState == 4 || xmlHttp.readyState == 0)
  {
    // retrieve the name typed by the user on the form
    message = encodeURIComponent(document.getElementById('message').value);
    // execute the quickstart.php page from the server
    xmlHttp.open("GET", "inc/php/validate.php?dataType=message&&message=" + message + "&&validateType=AJAX", 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('checkmessage()', 1000);
}

// executed automatically when a message is received from the server
function handleServerResponse() 
{
  // 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
     response = xmlDocumentElement.getElementsByTagName('responseMessage')[0].firstChild.nodeValue;
	divId = xmlDocumentElement.getElementsByTagName('responseDivID')[0].firstChild.nodeValue;

 // errorMessage = xmlDocumentElement.firstChild.data;   
   // update the client display using the data received from the server
   document.getElementById(divId).innerHTML = response;
   
  // restart sequence
   //   setTimeout('process()', 1000);
    } 
    // a HTTP status different than 200 signals an error
    else 
    {
      alert("There was a problem accessing the server: " + xmlHttp.statusText);
    }
  }
}