JQuery 无刷新查询_www.
   
   
        function openAjax() {
            var val = document.getElementById('txt').value;
            var url = "VerifyUserNameHandler.ashx?para=" + val + "&date=" + new Date();
            $.get(url, function (d) {
                $("#resultSpan").html(d);
            })
        }       
   


   
     用户名: 
   

using System;
using System.Web;
using System.Collections;
using System.Collections.Generic;
public class VerifyUserNameHandler : IHttpHandler {
   
    public void ProcessRequest (HttpContext context) {
        //context.Response.ContentType = "text/plain";
        string _name = context.Request.QueryString["para"];
        _name = string.IsNullOrEmpty(_name) ? "" : _name;           
        System.Threading.Thread.Sleep(3000);//用线程来模拟数据库查询工作
        string[] Names = new string[] { "Sandy", "阿非", "abc" };//这里用Names数组来代替数据库中的结果集
        if (Array.IndexOf(Names, _name) == -1)
        {
            context.Response.Write("恭喜，用户名可以使用。");
        }
        else
        {
            context.Response.Write("抱歉，用户名已被使用。");
        }
    }

    public bool IsReusable {
        get {
            return false;
        }
    }
}