//Gets the browser specific XmlHttpRequest Object
                        function getXmlHttpRequestObject() {
                                if (window.XMLHttpRequest) {
                                        return new XMLHttpRequest(); //Not IE
                                } else if(window.ActiveXObject) {
                                        return new ActiveXObject("Microsoft.XMLHTTP"); //IE
                                } else {
                                        //Display your error message here.
                                        //and inform the user they might want to upgrade
                                        //their browser.
                                        alert("Your browser doesn't support the XmlHttpRequest object.  Better upgrade to Firefox.");
                                }
                        }
                        //Get our browser specific XmlHttpRequest object.
                        var receiveReq = getXmlHttpRequestObject();
                        //Initiate the asyncronous request.
                        function linkCode() {
                                //If our XmlHttpRequest object is not in the middle of a request, start the new asyncronous call.
                                if (receiveReq.readyState == 4 || receiveReq.readyState == 0) {
                                        //Setup the connection as a GET call to linkcode.php.
                                        //True explicity sets the request to asyncronous (default).
                                        receiveReq.open("GET", 'linkcode.php', true);
                                        //Set the function that will be called when the XmlHttpRequest objects state changes.
                                        receiveReq.onreadystatechange = handleLinkCode;
                                        //Make the actual request.
                                        receiveReq.send(null);
                                }
                        }
                        //Called every time our XmlHttpRequest objects state changes.
                        function handleLinkCode() {
                                //Check to see if the XmlHttpRequests state is finished.
                                if (receiveReq.readyState == 4) {
                                        //Set the contents of our span element to the result of the asyncronous call.
                                        document.getElementById('span_result').innerHTML = receiveReq.responseText;
                                }
                        }