if(navigator.appVersion.indexOf("Mac") > 1){
//Mac
document.write('<link rel="stylesheet" href="essencevol5/mac.css">')
}else{
if(navigator.appName.charAt(0) == "M"){
//Win IE
document.write('<link rel="stylesheet" href="essencevol5/wie.css">')
}else{
//Win NN
document.write('<link rel="stylesheet" href="essencevol5/wnn.css">')
}
}