//Stylesheet Browserabhängig laden
 var agt=navigator.userAgent.toLowerCase();
 var app =navigator.appName.toLowerCase(); // "Microsoft Internet Explorer"
 var css = '';
 if ((agt.indexOf("mac")!=-1) && (app.indexOf("microsoft internet explorer"))) {
	css = '_mac';
  } else {
	if ((agt.indexOf("gecko")!=-1) || (agt.indexOf("firefox")!=-1)) {
		css = '_gecko';
	} else {
		css = '';
	}
  }
 csslink = "<link href='style" + css + ".css' rel='stylesheet' type='text/css'>";
 document.write(csslink);