var Zeile, CSSFile;

      if ((navigator.appName == "Microsoft Internet Explorer")
        &&(parseInt(navigator.appVersion.charAt(0))>= 4)
        &&(navigator.appVersion.lastIndexOf('Win')!= -1))
      	{
      	CSSFile="../css/win_ie.css";
      	}

      if ((navigator.appName == "Microsoft Internet Explorer")
        &&(parseInt(navigator.appVersion.charAt(0))>= 4)
        &&(navigator.appVersion.lastIndexOf('Mac')!= -1))
      	{
      	CSSFile="../css/mac_ie.css";
      	}

	  if ((navigator.appName == "Netscape")
        &&(parseInt(navigator.appVersion.charAt(0))>= 5)
        &&(navigator.appVersion.lastIndexOf('Win')!= -1))
      	{
		CSSFile="../css/win_nn6.css";
      	}
      if ((navigator.appName=="Netscape")
        &&(parseInt(navigator.appVersion.charAt(0))>= 5)
        &&(navigator.appVersion.lastIndexOf('Mac')!= -1))
      	{
      	CSSFile="../css/mac_nn6.css";
      	}
	  
	  if ((navigator.appName == "Netscape")
        &&(parseInt(navigator.appVersion.charAt(0))>= 4 && parseInt(navigator.appVersion.charAt(0))< 5)
        &&(navigator.appVersion.lastIndexOf('Win')!= -1))
      	{
      	CSSFile="../css/win_nn4.css";
      	}
      if ((navigator.appName=="Netscape")
        &&(parseInt(navigator.appVersion.charAt(0))>= 4 && parseInt(navigator.appVersion.charAt(0))< 5)
        &&(navigator.appVersion.lastIndexOf('Mac')!= -1))
      	{
      	CSSFile="../css/mac_nn4.css";
      	}

Zeile="<LINK REL=\"STYLESHEET\" HREF=\""+CSSFile+"\" TYPE=\"TEXT/CSS\">";
document.write(Zeile);