Browser Sniffer

<script type="text/javascript">

//CS1.1

var exclude=1;
var agt=navigator.userAgent.toLowerCase();
var win=0;var mac=0;var lin=1;
if(agt.indexOf('win')!=-1){win=1;lin=0;}
if(agt.indexOf('mac')!=-1){mac=1;lin=0;}
var lnx=0;if(lin){lnx=1;}
var ice=0;
var ie=0;var ie4=0;var ie5=0;var ie6=0;var com=0;var dcm;
var op5=0;var op6=0;var op7=0;
var ns4=0;var ns6=0;var ns7=0;var mz7=0;var kde=0;var saf=0;
if(typeof navigator.vendor!="undefined" && navigator.vendor=="KDE"){
	var thisKDE=agt;
	var splitKDE=thisKDE.split("konqueror/");
	var aKDE=splitKDE[1].split("; ");
	var KDEn=parseFloat(aKDE[0]);
	if(KDEn>=2.2){
		kde=1;
		ns6=1;
		exclude=0;
		}
	}
else if(agt.indexOf('webtv')!=-1){exclude=1;}
else if(typeof window.opera!="undefined"){
	exclude=0;
	if(/opera[\/ ][5]/.test(agt)){op5=1;}
	if(/opera[\/ ][6]/.test(agt)){op6=1;}
	if(/opera[\/ ][7-9]/.test(agt)){op7=1;}
	}
else if(typeof document.all!="undefined"&&!kde){
	exclude=0;
	ie=1;
	if(typeof document.getElementById!="undefined"){
		ie5=1;
		if(agt.indexOf("msie 6")!=-1){
			ie6=1;
			dcm=document.compatMode;
			if(dcm!="BackCompat"){com=1;}
			}
		}
	else{ie4=1;}
	}
else if(typeof document.getElementById!="undefined"){
	exclude=0;
	if(agt.indexOf("netscape/6")!=-1||agt.indexOf("netscape6")!=-1){ns6=1;}
	else if(agt.indexOf("netscape/7")!=-1||agt.indexOf("netscape7")!=-1){ns6=1;ns7=1;}
	else if(agt.indexOf("gecko")!=-1){ns6=1;mz7=1;}
	if(agt.indexOf("safari")!=-1 || (typeof document.childNodes!="undefined" && typeof document.all=="undefined" && typeof navigator.taintEnabled=="undefined")){mz7=0;ns6=1;saf=1;}
	}
else if((agt.indexOf('mozilla')!=-1)&&(parseInt(navigator.appVersion)>=4)){
	exclude=0;
	ns4=1;
	if(typeof navigator.mimeTypes['*']=="undefined"){
		exclude=1;
		ns4=0;
		}
	}
if(agt.indexOf('escape')!=-1){exclude=1;ns4=0;}
if(typeof navigator.__ice_version!="undefined"){exclude=1;ie4=0;}

</script>

      var	 returns 	Description
      		
      ie	0 	Internet Explorer 4+ and IE-based third-party browsers. You can also be more specific:
      ie4	0 	... Internet Explorer 4 only.
      ie5	0 	... Internet Explorer 5 or 6.
      ie6	0 	... Internet Explorer 6 only.

       
      ns4	0 	Netscape 4

       
      ns6	1 	Gecko and KDE-based browsers - which includes Netscape 6 and 7, Mozilla, Konqueror and Safari. You can also identify smaller groups within this:
      ns7	0 	... Netscape 7.
      mz7	1 	... any gecko browser except Netscape. This is principally designed to identify Mozilla's own builds from Version 0.6 onwards, but it also returns true for any other non-netscape gecko browser.
      kde	0 	... Konqueror, from KDE 2.2 onwards.
      saf	0 	... Safari. This variable will identify Safari irrespective of which browser it's set to identify as.

       
      op5	0 	Opera 5
      op6	0 	Opera 6
      op7	0 	Opera 7

      These variables will identify Opera irrespective of which browser it's set to identify as.

Underpinning these is a safety variable, for protecting legacy browsers:

      	
      exclude	0 	

There are also three OS variables:

      		
      win	1 	Windows
      mac	0 	Mac OS
      lin	0 	Linux, or anything else

and you can query a lower-case version of the user agent string:

      	
      agt	mozilla/5.0 (windows; u; windows nt 5.1; en-gb; rv:1.7.8) gecko/20050511 firefox/1.0.4 	

The sniffer variables are global, and therefore available to any other scripts on the same page. They allow you to code for or exclude specific browsers, eg:

if (mac&&ie5) { ... internet explorer 5 on a mac ... }
if (!ns4) { ... not netscape 4 ... }
if (win&&(op5||op6)) { ... a windows version of opera 5 or 6 ... }
if (ie5||ns6||op7) { ... ie5+, gecko, kde or opera 7 ... }

Remember that some browsers return true for more than one variable:

    * Explorer 6 returns true for (ie6) and also for (ie)
    * Explorer 5 or 6 return true for (ie5) and also for (ie)
    * Explorer 4 returns true for (ie4) and also for (ie)
    * Konqueror returns true for (kde) and also for (ns6)
    * Safari returns true for (saf) and also for (ns6)
    * All Gecko-based browsers which aren't Netscape return true for (mz7) and also for (ns6) 

The exclude variable returns true for all unspecified browsers. This is very useful for protecting them from scary DHTML, eg:

if (!exclude) { ... modern browsers only ... }

You may find it necessary to use a combination of expressions to get to the browser you need, eg:

if (!exclude) {
    if (ns6||op7) { ... gecko, KTHML or Opera 7 ... }
    else if (ie5) { ... internet explorer 5+ ... }
    else { ... any other dhtml browser ... }
    }

There are several minor browsers which have enough DHTML support to pass one of the object tests, but not enough to be useful. The script specifically filters out (adds to the exclude group) - Espial Escape, ICEBrowser and OmniWeb.