var bver = "nn2"; 
  var browserName = navigator.appName;
  var browserVersion = parseInt(navigator.appVersion);
  var layerok = false;
  var dynimok = false;

  var isIE = browserName.indexOf("Microsoft Internet Explorer")==-1?false:true;
  var isNN = browserName.indexOf("Netscape")==-1?false:true;
  var isOpera = browserName.indexOf("Opera")==-1?false:true;
  var isKonqueror = browserName.indexOf("Konqueror")==-1?false:true;
  var isDOM = document.getElementById?true:false;
  var isDomNN = document.layers?true:false;
  var isDomIE = document.all?true:false;
    
  if ( isNN && browserVersion >= 3) bver = "nn3";
  if ( isNN && browserVersion >= 4) bver = "nn4";
  if ( isNN && browserVersion >= 5) bver = "nn5";
  if ( isIE && browserVersion >= 3) bver = "ms3";
  if ( isIE && browserVersion >= 4) bver = "ms4";
  if ( isIE && navigator.userAgent.indexOf('MSIE 5') != -1 ) bver = "ms5";
  if ( isIE && navigator.userAgent.indexOf('MSIE 6') != -1 ) bver = "ms6";
  if ( isOpera && browserVersion >= 5) bver = "op5";

  if ( isNN && browserVersion>=3 ) dynimok=true;
  if ( isIE && browserVersion>=4 ) dynimok=true;
  if ( isOpera && browserVersion>=5 ) dynimok=true;
  if ( isKonqueror && browserVersion>=4 ) dynimok=true;
  if ( isNN && browserVersion>=4 ) layerok=true;
  if ( isIE && browserVersion>=4 ) layerok=true;
  if ( isOpera && browserVersion>=5 ) layerok=true;
  if ( isKonqueror && browserVersion>=4 ) layerok=true;

  var isMac = (navigator.appVersion.indexOf("Macintosh")!=-1?true:false)
  var isNNonMac = isMac && isNN