Gets the browser name and version

gistfile1.js

navigator.sayswho = (function () {
    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+(\.\d+)?)/g.exec(ua) || [];
        return 'IE ' + (tem[1] || '');
    }
    M = M[2] ? [M[1], M[2]] : [navigator.appName, navigator.appVersion, '-?'];
    if ((tem = ua.match(/version\/([\.\d]+)/i)) != null) M[2] = tem[1];
    return M.join(' ');
})();