var isNS4 = false;
var isIE4 = false;
var isW3C = false;
var displayNav = "";
var toggle = false;

if (document.layers) {  // NS 4 proprietary DOM
      isNS4 = true;
      docObj = "document.";
      styleObj = "";
}
else if (document.all && !document.getElementById) { // IE 4 proprietary DOM
      isIE4 = true;
      docObj = "document.all.";
      styleObj = ".style";
}
else if (document.getElementById && document.all) { // W3C standards-compliant DOM
      isW3C = true;
      docObj = "document.getElementById('";
      styleObj = "').style";
}
else if (document.getElementById) { // W3C standards-compliant DOM
      isW3C = true;
      docObj = "document.getElementById('";
      styleObj = "').style";
}