新手求指导

Question

textbox中输入用户名，若数据库中存在，则提示用户名存在！！ajax

Answer 1

http://www.cnblogs.com/zhzhqiu/archive/2009/02/27/1400027.html
看看这个！！

Answer 2

                 $.ajax({
                        url: "AjaxHandler/RegisterHandler.ashx",//ajax路径
                        data: { name: name },//传参数
                        cache: false,
                        async: true,
                        dataType: "text",
                        success: function (data) {
                            if (data == "1") {//判断返回值
                                alert("该昵称已存在");
                                return false;
                            }
                            else {
                                return true;
                            }
                        }
                    });