function yourOS() {
    var ua = navigator.userAgent.toLowerCase();
    if (ua.indexOf("win") != -1) {
        return "Windows";
    } else if (ua.indexOf("mac") != -1) {
        return "Macintosh";
    } else if (ua.indexOf("linux") != -1) {
        return "Linux";
    } else if (ua.indexOf("x11") != -1) {
        return "Unix";
    } else {
        return "Computers";
    }
}

function yourBrowser() {
    var br = navigator.appVersion.toLowerCase();
    if (br.indexOf("opera") != -1) {
        return "Opera";
    } else if (br.indexOf("safari") != -1) {
        return "Safari";
    } else if (br.indexOf("firefox") != -1) {
        return "Firefox";
    } else if (br.indexOf("chrome") != -1) {
        return "Chrome";
    } if (br.indexOf("ie") != -1) {
        return "Explorer";
    }
}

function CheckBrowser() {
    if (yourOS() == 'Macintosh' && yourBrowser() == 'Safari') {
        
    }

    var br = navigator;
    
    if (yourOS() == 'Windows' && br.appName == 'Opera') {
        
    }
}