// stores the reference to the XMLHttpRequest object
var xmlHttp = createXmlHttpRequestObject(); 
// holds the remote server address 
var serverAddress = "validate";
// 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;
}
var htaccess_flag = false;
// make asynchronous HTTP request using the XMLHttpRequest object 
function validate(htaccess)
{ 
	//alert (htaccess);
	if (!htaccess_flag) {
	  if (htaccess != 'active') {
	    serverAddress = serverAddress + '.php';
	    
	  }
	  htaccess_flag = true;
	}
	//alert (serverAddress);
	//return;
  // 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("txtEmail").value);
    // execute the quickstart.php page from the server
    xmlHttp.open("GET", serverAddress + "?email=" + email, 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('active')", 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
      helloMessage = xmlDocumentElement.getElementsByTagName("result")[0].firstChild.data;
      validUser    = xmlDocumentElement.getElementsByTagName("validuser")[0].firstChild.data;
      validPass    = xmlDocumentElement.getElementsByTagName("validpass")[0].firstChild.data;
      if (validUser == 0)
        document.forms['loginForm'].txtPassword.setAttribute('readOnly','readonly');
      if ((validUser == 1) && (validPass == 0)) {
        document.getElementById("changePassLink").style.display = '';
        document.getElementById("passContent").style.display = 'none';
      }
      else {
      	document.getElementById("changePassLink").style.display = 'none';
        document.getElementById("passContent").style.display = '';
        if ((validUser == 1) && (validPass == 1))
          document.forms['loginForm'].txtPassword.removeAttribute('readOnly');
      }
      // update the client display using the data received from the server
      document.getElementById("divMessage").innerHTML = 
                                            '<i>' + helloMessage  + '</i>';
      // restart sequence
      setTimeout("validate('active')", 1000);
    } 
    // a HTTP status different than 200 signals an error
    else 
    {
      alert("There was a problem accessing the server: " + xmlHttp.statusText);
    }
  }
}