validation

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using System.Text.RegularExpressions;

namespace WindowsFormsApplication1

{

public partial class Form1 : Form

{

public Form1()

{

InitializeComponent();

}

private void button1_Click(object sender, EventArgs e)

{

Match match = new Regex(@"^([\w\.\-]+)@([\w\-]+)((\.(\w){2,3})+)$").Match(textBox1.Text);

if (match.Success)

{

MessageBox.Show("Valid Email");

}

else MessageBox.Show("Invalid Email");

}