AJAX and PHP

AJAX Grid// handle receiving the server response with a new page of productsfunction handleGridPageLoad(){// when readyState is 4, we read the server responseif (xmlHttp.readyState == 4){// continue only if HTTP status is "OK"if (xmlHttp.status == 200){// read the responseresponse = xmlHttp.responseText;// server error?if (response.indexOf("ERRNO") >= 0|| response.indexOf("error") >= 0|| response.length == 0){// display error messagealert(response.length == 0 ? "Server serror." : response);// exit functionreturn;}// the server response in XML formatxmlResponse = xmlHttp.responseXML;// browser with native functionality?if (window.XMLHttpRequest && window.XSLTProcessor &&window.DOMParser){// load the XSLT documentvar xsltProcessor = new XSLTProcessor();xsltProcessor.importStylesheet(stylesheetDoc);// generate the HTML code for the new page of productspage = xsltProcessor.transformToFragment(xmlResponse, document);// display the page of productsvar gridDiv = document.getElementById(gridDivId);gridDiv.innerHTML = "";gridDiv.appendChild(page);}// Internet Explorer codeelse if (window.ActiveXObject){// load the XSLT documentvar theDocument = createMsxml2DOMDocumentObject();theDocument.async = false;theDocument.load(xmlResponse);// display the page of productsvar gridDiv = document.getElementById(gridDivId);gridDiv.innerHTML = theDocument.transformNode(stylesheetDoc);}}else{alert("Error reading server response.")}}}// enters the product specified by id into edit mode if editMode is true,// and cancels edit mode if editMode is falsefunction editId(id, editMode){// gets the element of the table that contains the tablevar productRow = document.getElementById(id).cells;// are we enabling edit mode?if(editMode){// we can have only one row in edit mode at one time214