var userAgent = navigator.userAgent.toLowerCase();
var isIEBrokenCSS = (userAgent.indexOf("msie") > -1);
var isOperaBrokenCSS = (userAgent.indexOf("opera") > -1);
var isWindows = (userAgent.indexOf("win") > -1);
var isMac = (userAgent.indexOf("mac") > -1);
var isLinux = (userAgent.indexOf("linux") > -1);
var isUnix = (userAgent.indexOf("unix") > -1);
if (isIEBrokenCSS && isWindows)
document.writeln('<link rel="stylesheet" href="/css/brokenIEWin.css" type="text/css" media="all" />');
if (isIEBrokenCSS && isMac)
document.writeln('<link rel="stylesheet" href="/css/brokenIEMac.css" type="text/css" media="all" />');
if (isOperaBrokenCSS)
document.writeln('<link rel="stylesheet" href="/css/brokenOpera.css" type="text/css" media="all" />');