javascript get browser name

1//gets the type of browser
2function detectBrowser() { 
3    if((navigator.userAgent.indexOf("Opera") || navigator.userAgent.indexOf('OPR')) != -1 ) {
4        return 'Opera';
5    } else if(navigator.userAgent.indexOf("Chrome") != -1 ) {
6        return 'Chrome';
7    } else if(navigator.userAgent.indexOf("Safari") != -1) {
8        return 'Safari';
9    } else if(navigator.userAgent.indexOf("Firefox") != -1 ){
10        return 'Firefox';
11    } else if((navigator.userAgent.indexOf("MSIE") != -1 ) || (!!document.documentMode == true )) {
12        return 'IE';//crap
13    } else {
14        return 'Unknown';
15    }
16} 

1var nVer = navigator.appVersion;
2var nAgt = navigator.userAgent;
3var browserName  = navigator.appName;
4var fullVersion  = ''+parseFloat(navigator.appVersion); 
5var majorVersion = parseInt(navigator.appVersion,10);
6var nameOffset,verOffset,ix;
7
8// In Opera 15+, the true version is after "OPR/" 
9if ((verOffset=nAgt.indexOf("OPR/"))!=-1) {
10 browserName = "Opera";
11 fullVersion = nAgt.substring(verOffset+4);
12}
13// In older Opera, the true version is after "Opera" or after "Version"
14else if ((verOffset=nAgt.indexOf("Opera"))!=-1) {
15 browserName = "Opera";
16 fullVersion = nAgt.substring(verOffset+6);
17 if ((verOffset=nAgt.indexOf("Version"))!=-1) 
18   fullVersion = nAgt.substring(verOffset+8);
19}
20// In MSIE, the true version is after "MSIE" in userAgent
21else if ((verOffset=nAgt.indexOf("MSIE"))!=-1) {
22 browserName = "Microsoft Internet Explorer";
23 fullVersion = nAgt.substring(verOffset+5);
24}
25// In Chrome, the true version is after "Chrome" 
26else if ((verOffset=nAgt.indexOf("Chrome"))!=-1) {
27 browserName = "Chrome";
28 fullVersion = nAgt.substring(verOffset+7);
29}
30// In Safari, the true version is after "Safari" or after "Version" 
31else if ((verOffset=nAgt.indexOf("Safari"))!=-1) {
32 browserName = "Safari";
33 fullVersion = nAgt.substring(verOffset+7);
34 if ((verOffset=nAgt.indexOf("Version"))!=-1) 
35   fullVersion = nAgt.substring(verOffset+8);
36}
37// In Firefox, the true version is after "Firefox" 
38else if ((verOffset=nAgt.indexOf("Firefox"))!=-1) {
39 browserName = "Firefox";
40 fullVersion = nAgt.substring(verOffset+8);
41}
42// In most other browsers, "name/version" is at the end of userAgent 
43else if ( (nameOffset=nAgt.lastIndexOf(' ')+1) < 
44          (verOffset=nAgt.lastIndexOf('/')) ) 
45{
46 browserName = nAgt.substring(nameOffset,verOffset);
47 fullVersion = nAgt.substring(verOffset+1);
48 if (browserName.toLowerCase()==browserName.toUpperCase()) {
49  browserName = navigator.appName;
50 }
51}
52// trim the fullVersion string at semicolon/space if present
53if ((ix=fullVersion.indexOf(";"))!=-1)
54   fullVersion=fullVersion.substring(0,ix);
55if ((ix=fullVersion.indexOf(" "))!=-1)
56   fullVersion=fullVersion.substring(0,ix);
57
58majorVersion = parseInt(''+fullVersion,10);
59if (isNaN(majorVersion)) {
60 fullVersion  = ''+parseFloat(navigator.appVersion); 
61 majorVersion = parseInt(navigator.appVersion,10);
62}
63
64document.write(''
65 +'Browser name  = '+browserName+'<br>'
66 +'Full version  = '+fullVersion+'<br>'
67 +'Major version = '+majorVersion+'<br>'
68 +'navigator.appName = '+navigator.appName+'<br>'
69 +'navigator.userAgent = '+navigator.userAgent+'<br>'
70)
71