php curl函数不保存cookie（cookie文件：空）

Question

i have problem that the "PHP" cURL function don't save the cookie !

curl function :

$file['cookie'] = "cooki";
function cURL_Page($url='',$var=''){
    global $file;
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_CONNECTTIMEOUT,20);
    curl_setopt($curl, CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.64 Safari/537.31');
    curl_setopt($curl, CURLOPT_REFERER, "http://www.libertyreserve.com/en/login");
    curl_setopt($curl, CURLOPT_FOLLOWLOCATION, true);
    if($var) {
    curl_setopt($curl, CURLOPT_POST, 1);
    curl_setopt($curl, CURLOPT_POSTFIELDS, $var);
    }
    curl_setopt($curl, CURLOPT_COOKIE,$file['cookie']);
    curl_setopt($curl, CURLOPT_COOKIEFILE,$file['cookie']);
    curl_setopt($curl, CURLOPT_COOKIEJAR,$file['cookie']);
    curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, 3);
    curl_setopt($curl, CURLOPT_HEADER, 0);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, TRUE);
    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, FALSE);
    $result = curl_exec($curl);
    curl_close($curl);
    return $result;
}

in the file "cooki" the are no results

p.s : i curl a https page

thanks all