// 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;
}

// make asynchronous HTTP request using the XMLHttpRequest object 
function process(j)
{
	document.getElementById( "msg" + j ).innerHTML = '<i>добавлено&nbsp;в&nbsp;любимые</i>';
	    //  alert(j);

  // 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
     name = encodeURIComponent(document.getElementById("it_" + j).value);
    // name = j
    // execute the quickstart.php page from the server
    xmlHttp.open("GET", "/add_playlist_item.php?name=" + name, 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('process()', 1000);
}

// make asynchronous HTTP request using the XMLHttpRequest object 
function del_item(j)
{
    //alert(j);
	document.getElementById( "msg" + j ).innerHTML = '<i>удалено</i>';
	    //  alert(j);

  // 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
     name = encodeURIComponent(document.getElementById("it_" + j).value);
    // name = j
    // execute the quickstart.php page from the server
    xmlHttp.open("GET", "/del_playlist_item.php?name=" + name, 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('del_item()', 1000);
}

// executed automatically when a message is received from the server
function handleServerResponse() 
{
 // alert(xmlHttp.status);
   //	document.getElementById( "msg" + name ).innerHTML = '<b>' + helloMessage + '</b>';
  // 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.firstChild.data;
      // update the client display using the data received from the server
      // alert("msg" + name);
      document.getElementById( "msg103900" ).innerHTML = 
                                            '<b>1' + helloMessage + '</b>';
      // 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);
    }
  }
}

