PHP curl的JavaScript实现

以下代码如何用JavaScript实现
$curl = curl_init($url);
curl_setopt($curl, CURLOPT_CUSTOMREQUEST, $method);
curl_setopt($curl, CURLOPT_HTTPHEADER, array("content-type: application/json"));
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_POSTFIELDS, $data);

$response = curl_exec($curl);
$err = curl_error($curl);
$http_code = curl_getinfo($curl, CURLINFO_HTTP_CODE);

curl_close($curl);

或者说ajax的跨域put请求如何实现

需要借助activex，纯js出于安全考虑不能跨域

ajax 的 jsonp 属性是可以跨域的

$.ajax({
 url:url,
 dataType:'jsonp',
 processData: false, 
 type:'get',
 success:function(data){
   alert(data.name);
 },
 error:function(XMLHttpRequest, textStatus, errorThrown) {
   alert(XMLHttpRequest.status);
   alert(XMLHttpRequest.readyState);
   alert(textStatus);
 }});