ua = navigator.userAgent.toLowerCase(),check = function(r){    return r.test(ua);},isStrict = document.compatMode == "CSS1Compat",isOpera = check(/opera/),isChrome = check(/chrome/),isWebKit = check(/webkit/),isSafari = !isChrome && check(/safari/),isSafari3 = isSafari && check(/version3/),isSafari4 = isSafari && check(/version4/),isIE = !isOpera && check(/msie/),isIE7 = isIE && check(/msie 7/),isIE8 = isIE && check(/msie 8/),isGecko = !isWebKit && check(/gecko/),isGecko3 = isGecko && check(/rv:1.9/),isBorderBox = isIE && !isStrict,isWindows = check(/windows|win32/),isMac = check(/macintosh|mac os x/),isAir = check(/adobeair/),isLinux = check(/linux/)