//OS の名称：document.userSystem.osLongName
//OS の略称：document.userSystem.osShortName
//ブラウザの名称：document.userSystem.browserLongName
//ブラウザの略称：document.userSystem.browserShortName
//ブラウザのバージョン：document.userSystem.browserVersion

var os      = document.userSystem.osShortName
var browser = document.userSystem.browserShortName
var b_ver   = document.userSystem.browserVersion

if(os == "win"){
	if(browser == "ie"){
		if(b_ver == "6.0"){
			cssfile = "http://www.asano.jp/culture/blog/styles-site_ie6.css";
		}else{
			cssfile = "http://www.asano.jp/culture/blog/styles-site.css";
		}
	}else{
		cssfile = "http://www.asano.jp/culture/blog/styles-site.css";
	}
}else if(os == "osx"){
	if(browser == "sf"){
		cssfile = "http://www.asano.jp/culture/blog/styles-site.css";
	}else{
		cssfile = "http://www.asano.jp/culture/blog/styles-site.css";
	}
}else if(os == "mac"){
	if(browser == "ie"){
		cssfile = "http://www.asano.jp/culture/blog/styles-site.css";
	}
}

document.write('<link href="'+ cssfile +'" type="text/css" rel="stylesheet" />');