<%@ Control Language="C#" AutoEventWireup="true" CodeFile="ContactForm.ascx.cs" Inherits="Controls_ContactForm" %>
<style type="text/css">
  .style1
  {
    width: 100%;
  }
</style>
<script type="text/javascript">
  function ValidatePhoneNumbers(source, args)
  {
    var phoneHome = document.getElementById('<%= PhoneHome.ClientID %>');
    var phoneBusiness = doc.getElementByID('<%= PhoneBusiness.ClientID %>');
    if (phoneHome.value != '' || phoneBusiness.value != '')
    {
      args.isValid = true;
    }
    else
    {
      args.isValid = false;
    }
  }
</script>
<table class="style1" runat="server" id="FormTable">
  <tr>
    <td colspan="3">
      <h1>
        Get in touch with us</h1>
      <p>
        Use the form below to get in touch with us.&nbsp; Enter your name, e-mail address,
        and your home or business phone number to get in touch with us.</p>
    </td>
  </tr>
  <tr>
    <td>
      Name
    </td>
    <td>
      <asp:TextBox ID="Name" runat="server"></asp:TextBox>
    </td>
    <td>
      <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="Name"
        CssClass="ErrorMessage" ErrorMessage="Enter your name">*</asp:RequiredFieldValidator>
    </td>
  </tr>
  <tr>
    <td>
      E-mail address
    </td>
    <td>
      <asp:TextBox ID="EmailAddress" runat="server"></asp:TextBox>
    </td>
    <td>
      <asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ControlToValidate="EmailAddress"
        CssClass="ErrorMessage" Display="Dynamic" ErrorMessage="Enter an e-mail address">*</asp:RequiredFieldValidator>
      <asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server" ControlToValidate="EmailAddress"
        CssClass="ErrorMessage" Display="Dynamic" ErrorMessage="Enter a valid e-mail address"
        ValidationExpression="\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*">*</asp:RegularExpressionValidator>
    </td>
  </tr>
  <tr>
    <td>
      Confirm e-mail address
    </td>
    <td>
      <asp:TextBox ID="ConfirmEmailAddress" runat="server"></asp:TextBox>
    </td>
    <td>
      <asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server" ControlToValidate="ConfirmEmailAddress"
        CssClass="ErrorMessage" Display="Dynamic" ErrorMessage="Confirm the e-mail address">*</asp:RequiredFieldValidator>
      <asp:CompareValidator ID="CompareValidator1" runat="server" ControlToCompare="EmailAddress"
        ControlToValidate="ConfirmEmailAddress" CssClass="ErrorMessage" Display="Dynamic"
        ErrorMessage="Retype the e-mail address">*</asp:CompareValidator>
    </td>
  </tr>
  <tr>
    <td>
      Home phone number
    </td>
    <td>
      <asp:TextBox ID="PhoneHome" runat="server" ClientIDMode="Static"></asp:TextBox>
    </td>
    <td>
      <asp:CustomValidator ID="CustomValidator1" runat="server" ClientValidationFunction="ValidatePhoneNumbers"
        CssClass="ErrorMessage" Display="Dynamic" ErrorMessage="Enter your home or business phone number"
        OnServerValidate="CustomValidator1_ServerValidate">*</asp:CustomValidator>
    </td>
  </tr>
  <tr>
    <td>
      Business phone number
    </td>
    <td>
      <asp:TextBox ID="PhoneBusiness" runat="server" ClientIDMode="Static"></asp:TextBox>
    </td>
    <td>
      &nbsp;
    </td>
  </tr>
  <tr>
    <td>
      Comments
    </td>
    <td>
      <asp:TextBox ID="Comments" runat="server" Height="101px" TextMode="MultiLine" Width="484px"></asp:TextBox>
    </td>
    <td>
      <asp:RequiredFieldValidator ID="RequiredFieldValidator4" runat="server" ControlToValidate="Comments"
        CssClass="ErrorMessage" Display="Dynamic" ErrorMessage="Enter a comment">*</asp:RequiredFieldValidator>
    </td>
  </tr>
  <tr>
    <td>
      &nbsp;
    </td>
    <td>
      <asp:Button ID="SendButton" runat="server" Text="Send" OnClick="SendButton_Click" />
    </td>
    <td>
      &nbsp;
    </td>
  </tr>
  <tr>
    <td colspan="3">
      <asp:ValidationSummary ID="ValidationSummary1" runat="server" CssClass="ErrorMessage" HeaderText="Please correct the following errors before you press the Send button:" 
        ShowMessageBox="True" ShowSummary="False" />
    </td>
  </tr>
</table>
<asp:Label ID="Message" runat="server" Text="Message Sent" Visible="false" />

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;        //Provides access to the File class for reading the file
using System.Net.Mail;  //Provides access tot he various mail related classes

public partial class Controls_ContactForm : System.Web.UI.UserControl
{
  protected void Page_Load(object sender, EventArgs e)
  {

  }
  protected void CustomValidator1_ServerValidate(object source, ServerValidateEventArgs args)
  {
    if (!string.IsNullOrEmpty(PhoneHome.Text) || !string.IsNullOrEmpty(PhoneBusiness.Text))
    {
      args.IsValid = true;
    }
    else
    {
      args.IsValid = false;
    }
  }
  protected void SendButton_Click(object sender, EventArgs e)
  {
    if (Page.IsValid)
    {
      string fileName = Server.MapPath("~/App_Data/ContactForm.txt");
      string mailBody = File.ReadAllText(fileName);

      mailBody = mailBody.Replace("##Name##", Name.Text);
      mailBody = mailBody.Replace("##Email##", EmailAddress.Text);
      mailBody = mailBody.Replace("##HomePhone##", PhoneHome.Text);
      mailBody = mailBody.Replace("##BusinessPhone##", PhoneBusiness.Text);
      mailBody = mailBody.Replace("##Comments##", Comments.Text);

      MailMessage myMessage = new MailMessage();
      myMessage.Subject = "Response from web site";
      myMessage.Body = mailBody;

      myMessage.From = new MailAddress("[email protected]", "Peter - Sender");
      myMessage.To.Add(new MailAddress("[email protected]", "Peter - Receiever"));

      SmtpClient mySmtpClient = new SmtpClient();
      mySmtpClient.Send(myMessage);

      Message.Visible = true;
      FormTable.Visible = false;
    }
  }
}

 
var phoneHome = document.getElementById('<%= PhoneHome.ClientID %>');
var phoneBusiness = doc.getElementByID('<%= PhoneBusiness.ClientID %>');