post方式发送请求报文

$url="http://www.test.com/04_demo_weather.php?id=5";
$ci=curl_init($url);
curl_setopt($ci, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($ci, CURLOPT_HEADER, );
curl_setopt($ci, CURLOPT_RETURNTRANSFER, );
curl_setopt($ci, CURLOPT_POST, );
$arr=array('u_name'=>'zhangsan','u_pwd'=>);
curl_setopt($ci, CURLOPT_POSTFIELDS, $arr);
$data=curl_exec($ci);
echo $data;