js获取客户端操作系统

一个项目中碰到的问题，页面标题和导航的字体在macosx下没有，因为不同的字体，相同的font-size，显示的大小也不一样，所以导致macosx下错位。想到的解决办法就是通过js的navigator.platform获取客户端的操作系统，然对针对macosx单独加个class,以下这段代码是在网上找的，其实就是个类似系统的对照表。

JS:

function detectOS() {
    var sUserAgent = navigator.userAgent;
    var isWin = (navigator.platform == "Win32") || (navigator.platform == "Windows");
    var isMac = (navigator.platform == "Mac68K") || (navigator.platform == "MacPPC") || (navigator.platform == "Macintosh") || (navigator.platform == "MacIntel");
    if (isMac) return "Mac";
    var isUnix = (navigator.platform == "X11") && !isWin && !isMac;
    if (isUnix) return "Unix";
    var isLinux = (String(navigator.platform).indexOf("Linux") > -1);
    if (isLinux) return "Linux";
    if (isWin) {
		var isWin2K = sUserAgent.indexOf("Windows NT 5.0") > -1 || sUserAgent.indexOf("Windows 2000") > -1;
		if (isWin2K) return "Win2000";
		var isWinXP = sUserAgent.indexOf("Windows NT 5.1") > -1 || sUserAgent.indexOf("Windows XP") > -1;
		if (isWinXP) return "WinXP";
		var isWin2003 = sUserAgent.indexOf("Windows NT 5.2") > -1 || sUserAgent.indexOf("Windows 2003") > -1;
		if (isWin2003) return "Win2003";
		var isWinVista= sUserAgent.indexOf("Windows NT 6.0") > -1 || sUserAgent.indexOf("Windows Vista") > -1;
		if (isWinVista) return "WinVista";
		var isWin7 = sUserAgent.indexOf("Windows NT 6.1") > -1 || sUserAgent.indexOf("Windows 7") > -1;
		if (isWin7) return "Win7";
    }
    return "other";
}

document.writeln("您的操作系统是：" + detectOS());