<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml" ><head runat="server"> <title>Untitled Page</title> <script language =javascript > function check() ...{ /**////注意javascript中正则表示式的写法: /表示式/ var rg= /^[w-]+(.[w-]+)*@[w-]+(.[w-]+)+$/; if(document.getElementById("txtid").value=="000") ...{ alert("Can't Be 000"); document.all("txtid").focus(); return false; } var str=document.getElementById("txtmail").value; if(!rg.test(str)) ...{ alert("Email Addess error!!"); document.all("txtmail").focus(); return false; } else ...{ return true; } } </script></head><body> <form id="form1" runat="server"> <asp:TextBox ID="txtmail" runat="server" Style="left: 270px; position: relative; top: 221px"></asp:TextBox>; <!--Notes: "OnClientClick" and "onclick" The Use of The 'Return'--> <asp:Button id="btuLogin" OnClientClick ="return check()" runat="server" Style="left: 211px; position: relative; top: 289px" Text="Button" OnClick="btuLogin_Click" /> <asp:TextBox ID="txtid" runat="server" Style="left: 48px; position: relative; top: 159px"></asp:TextBox> </form></body></html>