ajax异步通信

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title></title>
    <script language="javascript" type="text/javascript" src="jquery-1.8.0.min.js"></script>
    <script language="javascript">
        $(function () {
            $(":input").mouseenter(function () {
                $(this).css("border", "1px solid red");
            });
            $(":input").mouseout(function () {
                $(this).css("border", "1px solid black");
            });
        });
        var xmlHttp;
        function createXMLHttpRequest() {
            if (window.ActiveXObject)
                xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
            else if (window.XMLHttpRequest)
                xmlHttp = new XMLHttpRequest();
        }
        function startRequest() {
            createXMLHttpRequest();
            xmlHttp.open("GET", "Default.aspx", true);
            xmlHttp.onreadystatechange = function(){
                if (xmlHttp.readyState == 4 && xmlHttp.status == 200)
                    alert("服务器返回"+xmlHttp.responseText);
            }
            xmlHttp.send(null);
            //alert("服务器返回" + xmlHttp.responseText);
        }
    </script>
    <style type="text/css">
        .btn 
        {
            60px;
            border:1px solid red; 
            background-color:gray;
            color:Red;
        }
    </style>
</head>
<body>
<center>
<form>
<table>
<tr>
    <td><label>用户名</label></td><td><input type="text" name="name" /></td>
</tr>
<tr>
    <td><label>密码</label></td><td><input type="password" name="pass" /></td>
</tr>
<tr>
    <td></td><td align="center"><input type="button" value="OK" class="btn" />&nbsp<input type="reset" value="reset" class="btn" /></td>
</tr>
</table>
<p>Test JS</p>
<input type="button" value="测试异步通信" onclick="startRequest()" />
</form>
</center>
</body>
</html>
 
 
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" ContentType="text/html" ResponseEncoding="gb2312" %>
<%@ Import Namespace="System.Data" %>
<%
    Response.Write("异步测试成功,Hello!!");    
%>
原文地址:https://www.cnblogs.com/perock/p/2633620.html