function process()
{ var url = 'phptest.php';
 net.ContentLoader(url,handleServerResponse,null,"GET");
}
// handles the response received from the server
function handleServerResponse()
{
  // read the message from the server
  var xmlResponse = xmlHttp.responseXML;
  // catching potential errors with IE and Opera
  if (!xmlResponse || !xmlResponse.documentElement)
    throw("Invalid XML structure:\n" + xmlHttp.responseText);
  // catching potential errors with Firefox
  var rootNodeName = xmlResponse.documentElement.nodeName;
  if (rootNodeName == "parsererror") throw("Invalid XML structure");
  // obtain the XML's document element
  xmlRoot = xmlResponse.documentElement;  
  // obtain arrays with book titles and ISBNs 
  titleArray = xmlRoot.getElementsByTagName("title");
  isbnArray = xmlRoot.getElementsByTagName("isbn");
  // generate HTML output
  var html = "";  
  // iterate through the arrays and create an HTML structure
  for (var i=0; i<titleArray.length; i++)
    html += titleArray.item(i).firstChild.data + 
            ", " + isbnArray.item(i).firstChild.data + "<br/>";
  // obtain a reference to the <div> element on the page
  myDiv = document.getElementById("myDivElement");
  // display the HTML output
  myDiv.innerHTML = html;
}