$ch = curl_init();
curl_setopt($ch, CURLOPT_VERBOSE,       1);
curl_setopt($ch, CURLOPT_HEADER,        1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION,1);
curl_setopt($ch, CURLOPT_AUTOREFERER,   1);
curl_setopt($ch, CURLOPT_HTTPHEADER,    array('Expect:')); // remove Expect header to avoid 100 Continue situations
curl_setopt($ch, CURLOPT_USERAGENT,     'Mozilla [abbreviated]');
curl_setopt($ch, CURLOPT_CAINFO,        dirname(__FILE__).'/cacert.pem');
curl_setopt($ch, CURLOPT_COOKIEFILE,    dirname(__FILE__).'/cookie.hq.txt'); // write cookies
curl_setopt($ch, CURLOPT_COOKIEJAR,     dirname(__FILE__).'/cookie.hq.txt'); // read cookies
curl_setopt($ch, CURLOPT_COOKIESESSION, 1);
curl_setopt($ch, CURLOPT_URL,           'https://the_url.jsp');

$data = curl_exec($ch);
$error= curl_error($ch);
if(!empty($error))
    echo '<p>'.$error.'</p>';
else
    echo '<p>ok</p>';

curl_setopt($ch, CURLOPT_POST,       1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $options);
$data = curl_exec($ch);
$error=curl_error($ch);

$options.=urlencode($fieldName).'='.urlencode($element->getAttribute('value'));

$options.=urlencode($fieldName).'='.urlencode($element->getAttribute('value'));

<?php

 echo curl_grab_page("https://www.example.net/login.php", "https://www.example.net/", "username=foo&password=bar", "true",  "null", "false");

// $url = page to POST data
// $ref_url = tell the server which page you came from (spoofing)
// $login = true will make a clean cookie-file.
// $proxy = proxy data
// $proxystatus = do you use a proxy ? true/false

function
curl_grab_page($url,$ref_url,$data,$login,$proxy,$proxystatus){
    if($login == 'true') {
        $fp = fopen("cookie.txt", "w");
        fclose($fp);
    }
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_COOKIEJAR, "cookie.txt");
    curl_setopt($ch, CURLOPT_COOKIEFILE, "cookie.txt");
    curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)");
    curl_setopt($ch, CURLOPT_TIMEOUT, 40);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
    if ($proxystatus == 'true') {
        curl_setopt($ch, CURLOPT_HTTPPROXYTUNNEL, TRUE);
        curl_setopt($ch, CURLOPT_PROXY, $proxy);
    }
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);

    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_REFERER, $ref_url);

    curl_setopt($ch, CURLOPT_HEADER, TRUE);
    curl_setopt($ch, CURLOPT_USERAGENT, $_SERVER['HTTP_USER_AGENT']);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);
    curl_setopt($ch, CURLOPT_POST, TRUE);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
    ob_start();
    return curl_exec ($ch); // execute the curl command
    ob_end_clean();
    curl_close ($ch);
    unset($ch);
}