Javascript: Detect browser type

[js]
function get_browser_info(){
var ua=navigator.userAgent,tem,M=ua.match(/(opera|chrome|safari|firefox|msie|trident(?=\/))\/?\s*(\d+)/i) || [];
if(/trident/i.test(M[1])){
tem=/\brv[ :]+(\d+)/g.exec(ua) || [];
return {name:’IE ‘,version:(tem[1]||”)};
}
if(M[1]===’Chrome’){
tem=ua.match(/\bOPR\/(\d+)/)
if(tem!=null) {return {name:’Opera’, version:tem[1]};}
}
M=M[2]? [M[1], M[2]]: [navigator.appName, navigator.appVersion, ‘-?’];
if((tem=ua.match(/version\/(\d+)/i))!=null) {M.splice(1,1,tem[1]);}
return {
name: M[0],
version: M[1]
};
}
[/js]
[js]
var browser=get_browser_info();
alert(browser.name);
alert(browser.version);
[/js]