test.html
<html>
<head>
<title>表单验证</title>
<mce:script src="jquery-1.3.2.min.js" mce_src="jquery-1.3.2.min.js" type="text/javascript"></mce:script>
<mce:script type="text/javascript"><!--
$(function(){
$("#username").blur(function(){
$.get("checkname.ashx", {
username : $("#username").val()
}, function (data, textStatus){
$("#msg1").html(data).css("color","red");
}
);
})
})
// --></mce:script>
</head>
<body>
<form id="form1">
<p id="p1">用户名：<input type="text" name="username" id="username" /><span id="msg1"></span></p>
</form>
</body>
</html>
checkname.ashx
<%@ WebHandler Language="C#" Class="checkname" %>
using System;
using System.Web;
public class checkname : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "text/plain";
string username = context.Request.QueryString["username"];
if (username == "gdjlc")
context.Response.Write("对不起，此用户名已注册。");
else
context.Response.Write("恭喜，当前用户名可以注册。");
}
public bool IsReusable
{
get
{
return false;
}
}
}