// 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;
    }
  }
  //if(xmlHttp){xmlHttp.onreadystatechange = handleServerResponse;}
  // 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 process()
{
  document.getElementById("ibutton").innerHTML ="проверка...";
  // proceed only if the xmlHttp object isn't busy
  if (xmlHttp.readyState == 4 || xmlHttp.readyState == 0)
  {
    // execute the quickstart.php page from the server
	var cc1=document.getElementById('uLogin').value;
	var cc2=document.getElementById('uPass').value;
    xmlHttp.open("GET", "_enter.php?Login="+cc1+"&Password="+cc2, true);  
    // define the method to handle server responses
    xmlHttp.onreadystatechange = handleServerResponse;
    // make the server request
    xmlHttp.send(null);
  }
}

// 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
	  
	  if(!xmlResponse || !xmlResponse.documentElement){
	  	//alert("Неверная структура xml "+xmlHttp.responseText);
	  }
	
	  
	  xmlRoot = xmlResponse.documentElement;
	  var actArray=xmlRoot.getElementsByTagName("action");
	  var infoArray=xmlRoot.getElementsByTagName("info");
	  var d;
	  d=actArray.item(0).firstChild.data;
	  
	  if(d=="1"){
	  		d=infoArray.item(0).firstChild.data;
			document.getElementById("uenter").innerHTML ="<p style='text-align: left;'><br><br>"+d;
	  }
	  else{
	  	 document.getElementById("ibutton").innerHTML ="<img onclick='process();' class=noborder src='images/button1.gif' alt='Войти' title='Войти'>";
		 
	  	alert("Неверный логин или пароль");
	  }

      // update the client display using the data received from the server
     // document.getElementById("enter").innerHTML =Html;
	 // alert(d);
      // restart sequence
    } 
    // a HTTP status different than 200 signals an error
    else 
    {
      alert("There was a problem accessing the server: " + xmlHttp.statusText);
    }
  }
}