function checkUrl($url) {
    $agent = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:20.0) Gecko/20100101 Firefox/20.0";
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_USERAGENT, $agent);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_VERBOSE, false);
    curl_setopt($ch, CURLOPT_TIMEOUT, 5);
    $page = curl_exec($ch);
    $resp = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);
    if (($resp >= 200) && ($resp < 310))
        return true;
    else
        return false;
}

if (checkUrl("http://microsoft.com"))
    echo "Website UP
";
else
    echo "Website DOWN
";

if (checkUrl("http://microsoft1234567.com"))
    echo "Website UP
";
else
    echo "Website DOWN
";