$post_values="user=aaaaaa&pass=bbbb";
$o_ch = curl_init();
curl_setopt ($o_ch, CURLOPT_URL, $url);
curl_setopt ($o_ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (X11; U; SunOS sun4u; en-US; rv:1.0.1) Gecko/20020921 Netscape/7.0');
curl_setopt ($o_ch, CURLOPT_HEADER, 0);
curl_setopt ($o_ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt ($o_ch, CURLOPT_POST, 1);
curl_setopt ($o_ch, CURLOPT_POSTFIELDS, $post_values);
$html = curl_exec ($o_ch);
curl_close ($o_ch);
unset($o_ch);
echo $html;