var stylemac = 'css/mac.css';		//mac
var styleWinIE = 'css/win_ie.css';	//win_ie
var styleWinNN = 'css/win_nn.css';	//win_nn
if (!navigator.platform.match(/win/i)){
	var style = stylemac;
}else{
	if (navigator.appName.match(/microsoft/i)){
		var style = styleWinIE;
	}else{
		var style = styleWinNN;
	}
}
document.write('<link rel="stylesheet" href="'+style+'" type="text/css">');