HTML5跨域请求--POST方式

        var xmlHttp;

        // Create the XHR object.

        function createCORSRequest(method, url) {

            var xhr = new XMLHttpRequest();

            if ("withCredentials" in xhr) {

                // XHR for Chrome/Firefox/Opera/Safari.

                xhr.open(method, url, true);

            } else if (typeof XDomainRequest != "undefined") {

                // XDomainRequest for IE.

                xhr = new XDomainRequest();

                xhr.open(method, url);

            } else {

                // CORS not supported.

                xhr = null;

            }

            if (method == "POST") {

                xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");

            }

            return xhr;

        }

        // Helper method to parse the title tag from the response.

        function getTitle(text) {

            return text.match('<title>(.*)?</title>')[1];

        }

        //function callback() {

        //    if (xmlHttp.readyState == 4 && xmlHttp.status == 200) {

        //        var b = xmlHttp.responseText;

        //        alert(b);

        //    }

        //}

        // Make the actual CORS request.

        function makeCorsRequest(url) {

            // All HTML5 Rocks properties support CORS.

            xmlHttp = createCORSRequest('POST', url, true);

            //xmlHttp.onreadystatechange = callback;

            if (!xmlHttp) {

                alert('CORS not supported');

                return;

            }

            // Response handlers.

            xmlHttp.onload = function () {

                if (xmlHttp.readyState == 4 && xmlHttp.status == 200) {

                    var text = xmlHttp.responseText;

                    // var title = getTitle(text);

                    var resultDiv = document.getElementById("callbacktext");

                    resultDiv.innerHTML = text;

                    //alert('Response from CORS request to ' + text);

                }

            };

            xmlHttp.onerror = function () {

                alert('Woops, there was an error making the request.');

            };

            var params = "Email=" + $("#email").val();

            xmlHttp.send(params);

        }

        function urlDeal(url){

            //解决缓存的转换

            if (url.indexOf("?") >= 0) {

                url = url + "&t=" + (new Date()).valueOf();

            } else {

                url = url + "?+=" + (new Date()).valueOf();

            }

            //解决跨域的问题

            if (url.indexOf("http://") >= 0) {

                url.replace("?", "&");

                url = "Proxy?url=" + url;

            }

            return url;

        }

        var url = "请求的API地址";

        //var params = { "Email": "123123123@qq.com" };

        $("#btnPost").delegate("", "click", function () {

            makeCorsRequest(url);

        });