// JavaScript Document
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(folderpath, pageid, maxP, way)
{
  // proceed only if the xmlHttp object isn't busy
 
  
  if (xmlHttp.readyState == 4 || xmlHttp.readyState == 0)
  {
	  maxP=parseInt(maxP);
	 // alert(maxP);
	//alert(folderpath + "gallery_xml.php?prodid=" + pageid + "&pageid=" + prodid);  
	
    // retrieve the name typed by the user on the form
    // execute the quickstart.php page from the server
	if(typeof(prodid)=='undefined')
	{
		prodid=0;
	}
	if(way=='next')
	{
		prodid++;
	}
	if(way=='prev')
	{
		prodid--;
	}
	
	if(prodid==maxP)
	{
		prodid=0;
	}
	if(prodid==-1)
	{
		prodid=maxP-1;
	}
	
	//alert(prodid);
	
    xmlHttp.open("GET", folderpath + "gallery_xml.php?prodid=" + pageid + "&pageid=" + prodid, 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
      var xmlResponse = xmlHttp.responseXML;
	  
	  if(!xmlResponse || !xmlResponse.documentElement)
	  {
		throw("Invalid XML structure:\n" + xmlHttp.responseText);  
	  }
	  
	  var rootNodeName=xmlResponse.documentElement.nodeName;
	  
	  if(rootNodeName == "parserror")
	  {
		  throw("Invalid XML structure");
	  }
	  
	  xmlRoot=xmlResponse.documentElement;
	  
	  imgArray = xmlRoot.getElementsByTagName("obj1");
	 
      // obtain the document element (the root element) of the XML structure
     
	  
	
	//var txt=xmlDocumentElement.childNodes[1].childNodes[1].nodeValue;
	//var img=xmlDocumentElement.childNodes[3].childNodes[1].nodeValue;
	
	
	  
	  // get the text message, which is in the first child of
      // the the document element
	  imgr=imgArray.item(0).firstChild.data;
	  
	  //alert(imgr);
	  
	  img="<div class='g_img_back' style='background-image: url(" + imgr + ");'>&nbsp;</div>";
		
	  
   	     // update the client display using the data received from the server
	     document.getElementById('g_img').innerHTML = img;
		 
		
		 		 
		//alert(document.getElementById('cText'));
		//alert(document.getElementById('cImg'));
	  // restart sequence
    } 
    // a HTTP status different than 200 signals an error
    else 
    {
      alert("There was a problem accessing the server: " + xmlHttp.statusText);
    }
  }
}