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);
        });