protected void Button1_Click(object sender, System.EventArgs e)
    {
        Button btn = sender as Button;
        TextBox idd = btn.Parent.FindControl("t") as TextBox;
        TextBox tb = btn.Parent.FindControl("TextBox1") as TextBox;
    }

<%@ Page Language="C#" MasterPageFile="~/MasterPage.master" EnableEventValidation="false" AutoEventWireup="true" CodeFile="test.aspx.cs" Inherits="test" Title="Untitled Page" %>

 private void Button1_Click(object sender, EventArgs MyEventArgs)
    {
       
        Control myControl1 = FindControl("numbers");
        if (myControl1 != null)
        {

<table cellpadding="0" cellspacing="0">
<tr valign="top" >
    <td>Just nu har vi specialerbjudande på:
    </td>
</tr>
<tr>