客户端：
<head>
<title></title>
<script type="text/javascript">
function ajaxFunction() {
var xmlHttp;
try {
// Firefox, Opera 8.0+, Safari
xmlHttp = new XMLHttpRequest();
}
catch (e) {
// Internet Explorer
try {
xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
}
catch (e) {
try {
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}
catch (e) {
alert("您的浏览器不支持AJAX！");
return false;
}
}
}
xmlHttp.onreadystatechange = function () {
if (xmlHttp.readyState == 4) {
document.myForm.time.value = xmlHttp.responseText;
}
}
var dt = new Date();
xmlHttp.open("GET", "AjaxTime.ashx?dt=" + dt.getSeconds(), true); //
xmlHttp.send(null);
}
</script>
</head>
<body>
<form name="myForm">
用户: <input type="text" name="username" onkeyup="ajaxFunction();" />
时间: <input type="text" name="time" />
</form>
</body>
</html>
服务端：
public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "text/plain";
DateTime dt = DateTime.Now;
context.Response.Write(dt);
}