if (navigator.userAgent.toLowerCase().indexOf('chrome') > -1)
{
     var chromeCss = document.createElement("link");

     chromeCss.rel = "stylesheet";
     chromeCss.href = "style/ChromeStyle.css";

     document.getElementsByTagName("head")[0].appendChild(chromeCss);
}
if (navigator.userAgent.toLowerCase().indexOf('safari') > -1)
{
     var safariCss = document.createElement("link");

     safariCss.rel = "stylesheet";
     safariCss.href = "style/SafariStyle.css";

     document.getElementsByTagName("head")[0].appendChild(safariCss);
}