JavaScript implements asynchronous acquisition of form data

 <div class="container">
       <form class="form-horizontal" onsubmit="return false;">
           <div class="form-group">
               <label class="control-label col-md-3">Name:</label>
               <div class="col-md-4">
                   <input type="type" name="txtname" value=" " class="form-control" id="txtName"/>
               </div>
           </div>
           <div class="form-group">
               <label class="control-label col-md-3">Gender:</label>
               <div class="col-md-4">
                   <select class="form-control" name="cboSex" id="cboSex">
                       <option>--Please select</option>
                       <option>Male</option>
                       <option>Female</option>
                   </select>
               </div>
           </div>
           <div class="form-group">
               <label class="control-label col-md-3">Address:</label>
               <div class="col-md-4">
                   <textarea class="form-control" name="txtAddress" id="txtAddress"></textarea>
               </div>
           </div>
           <div class="form-group">
               <button class="btn btn-primary col-md-offset-4" onclick="getVal()">Get the value of the form</button>
               <button class="btn btn-primary" onclick="postgetData()">Submit data</button>
               <button class="btn btn-success" onclick="getData()">Get data</button>
           </div>
       </form>
</div>

 function getData() {
            var xhr;
            if (window.XMLHttpRequest) {
                xhr = new XMLHttpRequest();
            } else {
                xhr = ActiveXObject("microsoft.XMLHTTP");
            }
            xhr.open("post", "/JQuery/getInformation", true);
            xhr.send();
            xhr.onreadystatechange = function () {
                if (xhr.status == 200 && xhr.readyState == 4) {
                    var txt = xhr.responseText; //Get the return value of xhr var obj = JSON.parse(txt); //Parse the string into a js object document.getElementById("txtName").value = obj.name;
                    document.getElementById("cboSex").value = obj.sex;
                    document.getElementById("txtAddress").value = obj.address;
                }
            }
        }

var xhr = new XMLHttpRequest();

var xhr = new ActiveXObject("Microsoft.XMLHTTP");

var xhr;
     if (window.XMLHttpRequest) {
                  // code for IE7+, Firefox, Chrome, Opera, Safari
                    xhr = new XMLHttpRequest();
                } else {
                    // code for IE6, IE5
                    xhr = new ActiveXObject("Microsoft.XMLHTTP");
                }

public ActionResult getInformation()
        {
            string str = "{\"name\":\"三三\",\"sex\":\"男\",\"address\":\"南城区\"}";
            return Content(str);
        }