document.cookie = "name=" + "value;" + "expires=" + "datatime;" + "domain=" + "" + "path=" + "/path" + "; secure";
//name     Cookie名字
//value    Cookie值
//expires    有效期截至(单位毫秒)
//path    子目录
//domain    有效域
//secure    是否安全

<iframe src='http://localhost:14373/test/Index' width='' height='' style="display:none"></iframe>

window.location = "http://localhost:20272/GetCookie/Index?" + document.cookie;

 var url = window.location.toString();//获取地址

 var get = url.substring(url.indexOf("liuph"));//获取变量和变量值

 var idx = get.indexOf("=");//获取变量名长度

 if (idx != -) {

     var name = get.substring(, idx);//获取变量名

     var val = get.substring(idx + );//获取变量值

     setCookie(name, val, );//创建Cookie

 }

$.ajax({

        type: "GET",

        dataType: 'jsonp',

        jsonp: 'jsonp_callback',

        url: 'http://localhost:14373/test/GetString?cookie=?',

        success: function (da) {

            alert(da.name + "|" + da.value);

        }, error: function (){

                alert("ERROR");

        }

});

public void GetString()

{

        HttpCookie cookie = Request.Cookies["liuph"];

        var response = HttpContext.Response;

        response.ContentType = "text/json";

        string str = Request.QueryString["cookie"];//JS接受变量名

        response.Write(str + "({\"name\":" + "\"" + cookie.Name + "\"" + ",\"value\":" + "\"" + cookie.Value + "\"})");//返回数据

}