This article from: http://blog.sina.com.cn/s/blog_63a27dc501015h9j.html
Condition comment judgment browser <! -- [If! IE]> <! -- [If IE]> <! -- [If lt IE 6]> <! -- [If gte ie 6]>
<! -- [If! IE]> <! --> Both Internet Explorer and Internet Explorer can be recognized. <! -- <! [Endif] --> <! -- [If IE]> all IE identifiable <! [Endif] --> <! -- [If IE 6]> only IE6 can recognize <! [Endif] --> <! -- [If lt IE 6]> IE6 or earlier versions are recognizable <! [Endif] --> <! -- [If gte ie 6]> IE6 and IE6 or later versions are recognizable <! [Endif] --> <! -- [If IE 7]> only IE7 is recognizable <! [Endif] --> <! -- [If lt IE 7]> versions earlier than IE7 and IE7 are recognizable <! [Endif] --> <! -- [If gte ie 7]> IE7 and IE7 versions are recognizable <! [Endif] --> <! -- [If IE 8]> only IE8 is recognizable <! [Endif] --> <! -- [If IE 9]> only ie9 can recognize <! [Endif] -->