engine = null;
        if (window.navigator.appName == "Microsoft Internet Explorer") {
            // This is an IE browser. What mode is the engine in?
            if (document.documentMode) // IE8 or later
                engine = document.documentMode;
            else // IE 5-7
            {
                engine = 5; // Assume quirks mode unless proven otherwise
                if (document.compatMode) {
                    if (document.compatMode == "CSS1Compat")
                        engine = 7; // standards mode
                }
                // There is no test for IE6 standards mode because that mode  
                // was replaced by IE7 standards mode; there is no emulation.
            }
            // the engine variable now contains the document compatibility mode.
        }