var browserdetect=navigator.vendor;  

if (/Firefox[\/\s](\d+\.\d+)/.test(navigator.userAgent)){ 
 var ffversion=new Number(RegExp.$1)
 if (ffversion>=3)
   document.write("<link href='/css/csstest2.css' rel='StyleSheet' type='text/css' />")
 else if (ffversion>=2)
   document.write("<link href='/css/csstest2.css' rel='StyleSheet' type='text/css' />")
 else if (ffversion>=1)
   document.write("<link href='/css/csstest2.css' rel='StyleSheet' type='text/css' />")
}
else if (undefined != browserdetect)
{ 
    if (browserdetect.indexOf("Apple") >= 0) 
        {
             document.write("<link href='/css/csssafari.css' rel='StyleSheet' type='text/css' />")
        }
}    
else
{
    document.write("<link href='/css/csstest.css' rel='StyleSheet' type='text/css' />")
}