/// <summary>
/// Validates the email.
/// </summary>
/// <param name="sender">The sender.</param>
/// <param name="e">The <see cref="System.Web.UI.WebControls.ServerValidateEventArgs"/> instance containing the event data.</param>
/// <param name="page">The calling <see cref="System.Web.UI.Page" /> web page.</param>
public void ValidateEmail(object sender, ServerValidateEventArgs e, Page page)
{
    var emailAddress = page.FindControl("emailAddress") as TextBox;
    var firstName = page.FindControl("firstName") as TextBox;

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Text.RegularExpressions;
using System.Text;
using System.IO;
using System.Reflection;

using System;  
using System.Net;  
using System.Text.RegularExpressions;  
using System.IO;  
  
class TestHarness  
{  
  
    public static void Main()  
    {  

string Replace(string input, string replacement);  
string Replace(string input, string replacement, int count);  
string Replace(string input, string replacement, int count, int startat);  
static string Replace(string input, string pattern, string replacement);  
static string Replace(string input, string pattern, string replacement, RegexOptions options);  

using System;
using System.Configuration;
 
namespace Microsoft.Samples.AspNet.Validators
{
  class UsingRegexStringValidator
  {
    static void Main(string[] args)
    {
      // Display title.