document.write("<link rel=\"stylesheet\" href=\"/stylesheets/default.css\" type=\"text/css\" />");

var isNS4 = (document.layers) ? true : false;
var isNS6 = (!document.all && document.getElementById) ? true : false;
var ie = (navigator.appName.indexOf('Microsoft') != -1) ? true : false;
var isIE5 = (ie && document.getElementById && navigator.userAgent.indexOf('MSIE 6.0') == -1) ? true : false;
var isIE6 = (ie && document.getElementById && !isIE5) ? true : false;

if (isNS4) {
  document.write("<link rel=\"stylesheet\" href=\"/stylesheets/nn4.css\" />");
} else {
  document.write("<link rel=\"stylesheet\" href=\"/stylesheets/ie.css\" />");
}
if (isNS6) {
  document.write("<link rel=\"stylesheet\" href=\"/stylesheets/nn6.css\" />");
}
if (isIE6) {
  document.write("<link rel=\"stylesheet\" href=\"/stylesheets/ie6.css\" />");
}