偵測瀏覽器

use "navigator.userAgent"

IE9:
User-agent header: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; MAAU; OfficeLiveConnector.1.5; OfficeLivePatch.1.3; InfoPath.2; .NET4.0C; .NET4.0E)

Chrome:
User-agent header: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.11 (KHTML, like Gecko) Chrome/17.0.963.66 Safari/535.11

Firefox:
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:10.0.2) Gecko/20100101 Firefox/10.0.2


Safari:
User-agent header: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/534.52.7 (KHTML, like Gecko) Version/5.1.2 Safari/534.52.7