<asp:RegularExpressionValidator ValidationGroup="Anagrafica" ID="RegularExpressionValidatorEmail"
                                                    ControlToValidate="TextBoxEmail" ValidationExpression="\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*"
                                                    ErrorMessage="Indirizzo email immesso non valido" EnableClientScript="true" runat="server" />

//Email regex validator
Regex regex = new Regex(@"\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*");
 
//Website regex validator
Regex regex = new Regex(@"^http\://[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}(/\S*)?$");
 
//Comments on forum regex validator (max 4000 characters)
Regex regex = new Regex(@"^[+_%@:,.'!?"\\\^\&\#\$\*\(\)\-\/a-zA-Z0-9\s]{1,4000}$");

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;