1、导入jQuery.js代码 <asp:TextBox ID="txtname" onblur="checkUsername(this.value);" class="txt" runat="server"></asp:TextBox><br /> <span id="mes_username" style="margin-left: 60px;"> //验证用户名 function checkUsername(username) { var username = $.trim(username); if (username.length == 0) { $("#mes_username").html("<img src='images/check_error.gif' align='absmiddle' /> <span style='color:red'>请输入用户名</span>"); return; } else { var reg = /^[a-zA-Z0-9]{6,20}$/g; if (!reg.test(username)) { $("#mes_username").html("<img src='images/check_error.gif' align='absmiddle' /> <span style='color:red'>用户名必须为6-20数字或英文的组合</span>"); return; } else { var url = "handler/CheckUserName.ashx?username=" + username + "&t=" + new Date().valueOf(); //AJAX使用一般处理程序验证 $.get(url, function (data) { if (data == "false") { $("#mes_username").html("<img src='images/check_error.gif' align='absmiddle' /> <span style='color:red'>该用户名已存在</span>"); return; } else { $("#mes_username").html("<img src='images/access_allow.gif' align='absmiddle' /> <span style='color:red'></span>"); return; } }); } } } //验证密码6-20个数字或英文字符 function checkpwd(pwd) { var pwd = $.trim(pwd); if (pwd.length == 0) { $('#mes_pwd').html("<img src='images/wrong.png' /> <span style='color: Red;'>请输入密码</span>"); return; } else { var reg = /^[a-zA-Z0-9]{6,20}$/g; if (!reg.test(pwd)) { $('#mes_pwd').html("<img src='images/wrong.png' /> <span style='color: Red;'>密码长度必须大于6个字符小于20个字符</span>"); return; } else { $('#mes_pwd').html("<img src='images/right.png' />"); return; } } } //常规验证。弹出提示框的形式 <asp:Button ID="btnAdd" OnClientClick="return checkform();" runat="server" Text="提交信息" /> function checkform() { var name = $.trim($('#<%=txtusername.ClientID %>').val()); var pwd = $.trim($('#<%=txtpwd.ClientID %>').val()); var cpwd = $.trim($('#<%=txtcpwd.ClientID %>').val()); var question = $.trim($('#<%=txtquestion.ClientID %>').val()); var answer = $.trim($('#<%=txtanswer.ClientID %>').val()); var email = $.trim($('#<%=txtemail.ClientID %>').val()); if (name.length == 0 || pwd.length == 0 || cpwd.length == 0 || question.length == 0 || answer.length == 0 || email.length == 0) { alert("请输入完整信息再提交"); return false; } } 创建:CheckUsername.ashx一般处理程序 string username = context.Request.QueryString["username"]; if (string.IsNullOrEmpty(username)) { context.Response.Write("false"); context.Response.End(); } if (new DAL.UserDAL().ExistsUserName(username)) { context.Response.Write("false"); context.Response.End(); } else { context.Response.Write("true"); context.Response.End(); }