var xHRObject = false;
  
  if (window.ActiveXObject)
  {
  xHRObject = new ActiveXObject("Microsoft.XMLHTTP");
  }
  else if (window.XMLHttpRequest)
  {
  xHRObject = new XMLHttpRequest();
  }
  
  function getBody(action)
  {
       var argument = "book=";
       argument += encodeURI(document.getElementById("book").innerHTML); 
       argument += "&ISBN=";
       argument += encodeURI(document.getElementById("ISBN").innerHTML); 
       argument += "&authors=";
       argument += encodeURI(document.getElementById("authors").innerHTML); 
       argument += "&price=";
       argument += encodeURI(document.getElementById("price").innerHTML); 
       argument += "&action=";
       argument += encodeURI(action);
       return argument;
  }
  
  function getData()
  {
      if ((xHRObject.readyState == 4) &&(xHRObject.status == 200))
      {
            if (window.ActiveXObject)
            {
              //Load XML
              var xml = xHRObject.responseXML;
         
              //Load XSL
              var xsl = new ActiveXObject("Microsoft.XMLDOM");
              xsl.async = false;
              xsl.load("Cart.xsl");
              
              //Transform
              var transform = xml.transformNode(xsl);
              var spanb = document.getElementById("cart");
              spanb.innerHTML = transform; 
            }
            else
            {
                
                var xsltProcessor = new XSLTProcessor();
                
                //Load XSL
                xslStylesheet = document.implementation.createDocument("", "doc", null);
                xslStylesheet.async = false;
                xslStylesheet.load("Cart.xsl"); 
                xsltProcessor.importStylesheet(xslStylesheet);
  
                //Load XML
                xmlDoc = xHRObject.responseXML;
                
                //Transform
                var fragment = xsltProcessor.transformToFragment(xmlDoc, document);
                document.getElementById("cart").innerHTML = new XMLSerializer().serializeToString(fragment);
              }
           }
  }
  
  function AddRemoveItem(action)
  {
             var book  = document.getElementById("book").innerHTML;
             var bodyofform = getBody( action); 
             xHRObject.open("POST", <cartdisplay.php>, true);
             xHRObject.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
             xHRObject.onreadystatechange = getData;
             xHRObject.send(bodyofform); 
  }