How can you detect the version of a browser?

Question

I\'ve been searching around for code that would let me detect if the user visiting the website has Firefox 3 or 4. All I have found is code to detect the type of browser but

Answer 1

function BrowserCheck()
{
    var N= navigator.appName, ua= navigator.userAgent, tem;
    var M= ua.match(/(opera|chrome|safari|firefox|msie|trident)\/?\s*(\.?\d+(\.\d+)*)/i);
    if(M && (tem= ua.match(/version\/([\.\d]+)/i))!= null) {M[2]=tem[1];}
    M= M? [M[1], M[2]]: [N, navigator.appVersion,'-?'];
    return M;
}

This will return an array, first element is the browser name, second element is the complete version number in string format.