Miscellany

                if (window.ActiveXObject) { // IE
                        try {
                                http_request = new ActiveXObject("Msxml2.XMLHTTP");
                        }
                        catch (e) {
                                try {
                                        http_request = new ActiveXObject("Microsoft.XMLHTTP");
                                }
                                catch (e) {}
                        }
                }
                else { // Mozilla
                        IE = false;
                        http_request = new XMLHttpRequest();
                }