学步园

// Browser Detect Lite  v2.1
// http://www.dithered.com/javascript/browser_detect/index.html
// modified by Chris Nott (chris@NOSPAMdithered.com - remove NOSPAM)
//
// modified by Michael Lovitt to include OmniWeb and Dreamcast

function BrowserDetectLite() {
 var ua = navigator.userAgent.toLowerCase();
 this.ua = ua;

 // browser name
 this.isGecko     = (ua.indexOf('gecko') != -1);
 this.isMozilla   = (this.isGecko && ua.indexOf("gecko/") + 14 == ua.length);
 this.isNS        = ( (this.isGecko) ? (ua.indexOf('netscape') != -1) : ( (ua.indexOf('mozilla') != -1) && (ua.indexOf('spoofer') == -1) && (ua.indexOf('compatible') == -1) && (ua.indexOf('opera') == -1) && (ua.indexOf('webtv') == -1) && (ua.indexOf('hotjava') == -1) ) );
 this.isIE        = ( (ua.indexOf("msie") != -1) && (ua.indexOf("opera") == -1) && (ua.indexOf("webtv") == -1) );
 this.isOpera     = (ua.indexOf("opera") != -1);
 this.isKonqueror = (ua.indexOf("konqueror") != -1);
 this.isIcab      = (ua.indexOf("icab") != -1);
 this.isAol       = (ua.indexOf("aol") != -1);
 this.isWebtv     = (ua.indexOf("webtv") != -1);
 this.isOmniweb   = (ua.indexOf("omniweb") != -1);
 this.isDreamcast   = (ua.indexOf("dreamcast") != -1);
 
 // spoofing and compatible browsers
 this.isIECompatible = ( (ua.indexOf("msie") != -1) && !this.isIE);
 this.isNSCompatible = ( (ua.indexOf("mozilla") != -1) && !this.isNS && !this.isMozilla);
 
 // browser version
 this.versionMinor = parseFloat(navigator.appVersion);
 
 // correct version number for NS6+
 if (this.isNS && this.isGecko) {
  this.versionMinor = parseFloat( ua.substring( ua.lastIndexOf('/') + 1 ) );
 }
 
 // correct version number for IE4+
 else if (this.isIE && this.versionMinor >= 4) {
  this.versionMinor = parseFloat( ua.substring( ua.indexOf('msie ') + 5 ) );
 }
 
 // correct version number for Opera
 else if (this.isOpera) {
  if (ua.indexOf('opera/') != -1) {
   this.versionMinor = parseFloat( ua.substring( ua.indexOf('opera/') + 6 ) );
  }
  else {
   this.versionMinor = parseFloat( ua.substring( ua.indexOf('opera ') + 6 ) );
  }
 }
 
 // correct version number for Konqueror
 else if (this.isKonqueror) {
  this.versionMinor = parseFloat( ua.substring( ua.indexOf('konqueror/') + 10 ) );
 }
 
 // correct version number for iCab
 else if (this.isIcab) {
  if (ua.indexOf('icab/') != -1) {
   this.versionMinor = parseFloat( ua.substring( ua.indexOf('icab/') + 6 ) );
  }
  else {
   this.versionMinor = parseFloat( ua.substring( ua.indexOf('icab ') + 6 ) );
  }
 }
 
 // correct version number for WebTV
 else if (this.isWebtv) {
  this.versionMinor = parseFloat( ua.substring( ua.indexOf('webtv/') + 6 ) );
 }
 
 this.versionMajor = parseInt(this.versionMinor);
 this.geckoVersion = ( (this.isGecko) ? ua.substring( (ua.lastIndexOf('gecko/') + 6), (ua.lastIndexOf('gecko/') + 14) ) : -1 );
 
 // platform
 this.isWin   = (ua.indexOf('win') != -1);
 this.isWin32 = (this.isWin && ( ua.indexOf('95') != -1 || ua.indexOf('98') != -1 || ua.indexOf('nt') != -1 || ua.indexOf('win32') != -1 || ua.indexOf('32bit') != -1) );
 this.isMac   = (ua.indexOf('mac') != -1);
 this.isUnix  = (ua.indexOf('unix') != -1 || ua.indexOf('linux') != -1 || ua.indexOf('sunos') != -1 || ua.indexOf('bsd') != -1 || ua.indexOf('x11') != -1)
 
 // specific browser shortcuts
 this.isNS4x = (this.isNS && this.versionMajor == 4);
 this.isNS40x = (this.isNS4x && this.versionMinor < 4.5);
 this.isNS47x = (this.isNS4x && this.versionMinor >= 4.7);
 this.isNS4up = (this.isNS && this.versionMinor >= 4);
 this.isNS6x = (this.isNS && this.versionMajor == 6);
 this.isNS6up = (this.isNS && this.versionMajor >= 6);
 
 this.isIE4x = (this.isIE && this.versionMajor == 4);
 this.isIE4up = (this.isIE && this.versionMajor >= 4);
 this.isIE5x = (this.isIE && this.versionMajor == 5);
 this.isIE55 = (this.isIE && this.versionMinor == 5.5);
 this.isIE5up = (this.isIE && this.versionMajor >= 5);
 this.isIE6x = (this.isIE && this.versionMajor == 6);
 this.isIE6up = (this.isIE && this.versionMajor >= 6);
 
 this.isIE4xMac = (this.isIE4x && this.isMac);
}
var browser = new BrowserDetectLite();