// JavaScript Document
var csstype="external"
var mac_externalcss='css/mainmac.css' 
var pc_externalcss='css/mainpc.css'
var mactest=navigator.userAgent.indexOf("Mac")!=-1
if (csstype=="external")
document.write('<link rel="stylesheet" type="text/css" href="'+ (mactest? mac_externalcss : pc_externalcss) +'">')