function getOSType(){
    var uAgent  = navigator.userAgent.toUpperCase();
    if (uAgent.indexOf("MAC") >= 0) return "Mac";
    if (uAgent.indexOf("WIN") >= 0) return "Windows";
    return "";
}

function getBrowserName(){
    var uaName  = navigator.userAgent.toUpperCase();
	if (uaName.indexOf("FIREFOX",0) > -1) return "firefox";
	if (uaName.indexOf("SAFARI",0) > -1) return "safari";
	if (uaName.indexOf("OPERA",0) > -1) return "opera";
	if (uaName.indexOf("MSIE",0) > -1) return "ie";
	if (uaName.indexOf("NETSCAPE",0) > -1) return "nn";
    return "";
}


var cssDir = 'http://www.sdc.ac.jp/assets/css/os/';
var cssTags = '<link rel="stylesheet" type="text/css" href="';
var os = getOSType();
var browser = getBrowserName();
var fileName;
if (os == "Mac")   fileName = "mac";
if (os == "Windows") fileName = "win";
if (browser == "firefox") fileName += "firefox";
if (browser == "safari") fileName += "safari";
if (browser == "opera") fileName += "opera";
if (browser == "nn") fileName += "nn";
if (browser == "ie") fileName += "ie";
document.write(cssTags+cssDir+fileName+'.css">');
/*alert(cssDir+fileName);*/