<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="Login" %> <!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 id="Head1" runat="server"> <title>Simple Login Page</title> </head> <body> <form id="form1" runat="server"> <div> Username:<br /> <asp:TextBox id="usernameTextBox" runat="server" /> <asp:RequiredFieldValidator id="usernameReq" runat="server" ControlToValidate="usernameTextBox" ErrorMessage="Username is required!" SetFocusOnError="True" /> Password and Confirmation:<br /> <asp:TextBox id="passwordTextBox" runat="server" TextMode="Password" /> <asp:RequiredFieldValidator id="passwordReq" runat="server" ControlToValidate="passwordTextBox" ErrorMessage="Password is required!" SetFocusOnError="True" Display="Dynamic" /> <asp:TextBox id="confirmPasswordTextBox" runat="server" TextMode="Password" /> <asp:RequiredFieldValidator id="confirmPasswordReq" runat="server" ControlToValidate="confirmPasswordTextBox" ErrorMessage="Password confirmation is required!" SetFocusOnError="True" Display="Dynamic" /> <asp:CompareValidator id="comparePasswords" runat="server" ControlToCompare="passwordTextBox" ControlToValidate="confirmPasswordTextBox" ErrorMessage="Your passwords do not match up!" Display="Dynamic" /> <!-- Age --> Age:<br /> <asp:TextBox id="ageTextBox" runat="server" /> <asp:RequiredFieldValidator id="ageReq" runat="server" ControlToValidate="ageTextBox" ErrorMessage="Age is required!" SetFocusOnError="True" Display="Dynamic" /> <asp:CompareValidator id="ageCheck" runat="server" Operator="GreaterThan" Type="Integer" ControlToValidate="ageTextBox" ValueToCompare="15" ErrorMessage="You must be 16 years or older to log in" /> <asp:Button id="submitButton" runat="server" Text="Submit" OnClick="submitButton_Click" /> </div> </form> </body> </html> File: Default.aspx.cs using System; using System.Data; using System.Configuration; using System.Collections; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls; public partial class Login : System.Web.UI.Page { protected void submitButton_Click(object sender, EventArgs e) { if (Page.IsValid) { submitButton.Text = "Valid"; } else { submitButton.Text = "Invalid!"; } } }