try this
setcookie('cookie_name', 'cookie_value', time());
echo $_COOKIE['cookie_name'];
Now check the cookie if it exists.
if(isset($_COOKIE['cookie_name'])) {
echo "your cookie is set";
} else {
echo "return error or any thing you want";
}
This will give you all browser(s) information.
echo $_SERVER['HTTP_USER_AGENT'];