netscape4 = (document.layers) ? 1:0;     // Browserweiche für N4
if (netscape4)
 {
  document.writeln('<link rel="stylesheet" href="style_n4.css" type="text/css">');
 }
else
 {
  document.writeln('<link rel="stylesheet" href="style.css" type="text/css">');
 }