How to send a header with a username & password

Look, what I'm doing is posting values and retreiving the HTML of that page where I'm posting them to

<?

function sendToHost($host,$method,$path,$data,$useragent=0)
{
    // Supply a default method of GET if the one passed was empty
    if (empty($method))
         $method = 'GET';
    $method = strtoupper($method);
    $fp = fsockopen($host,80);
    if ($method == 'GET')
         $path .= '?' . $data;
    fputs($fp, "$method $path HTTP/1.1\n");
    fputs($fp, "Host: $host\n");
    fputs($fp, "Content-type: application/x-www-form-urlencoded\n");
    fputs($fp, "Content-length: " . strlen($data) . "\n");
    if ($useragent)
         fputs($fp, "User-Agent: MSIE\n");
    fputs($fp, "Connection: close\n\n");
    if ($method == 'POST')
         fputs($fp, $data);

    while (!feof($fp))
         $buf .= fgets($fp,128);
    fclose($fp);
    return $buf;
}


echo sendToHost('www.domain.com','post','/va/post.php','var1=diana');

?>


My problem is that I want to use this function but to a page that I usually access like this http://user:pass@www.domain.com/va/ppp.php

It uses authentication... How can I send the username and password values?