geting hidden field value in .ascx.cs file

Hey m not able to retrieve the hidden fileld(hiddenfield) value in Program.ascx.cs from Program.ascx file

<%@ Control Language="c#" AutoEventWireup="false" Codebehind="Program.ascx.cs" Inherits="a.b.c.Program" TargetSchema="http://schemas.microsoft.com/intellisense/ie5"%>
<%@ Import namespace="System.Text" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head id ="Head1" runat="server">
<script type="text/javascript">
function ConfirmIt() {
var x = confirm("Do you Want to notify changes to User ??");
var control = '<%=hiddenfield.ClientID%>';
if (x == true) {
document.getElementById(control).value = "1";
}
else {
document.getElementById(control).value = "0";
}
}
</script>
</head>
<body>
<form id="form1" runat="server">
<SCRIPT language="javascript" src="js/calendar.js">

</SCRIPT>
<script event="onbeforeunload" for="window">
showWaitMessage();
</script>

<TABLE style="FONT-SIZE: xx-small; FONT-FAMILY: verdana" cellPadding="2">
<TR>
<TD>
<asp:label id="StartDate" Font-Size="XX-Small" Font-Names="Verdana" Text="Add "
Runat="server" Font-Name="Verdana">Start Date (mm/dd/yy):</asp:label></TD>
<TD>
<asp:TextBox style="TEXT-ALIGN: center" Wrap="False" MaxLength="10" id="StartDate" Height="18px"
runat="server" Width="75"></asp:TextBox></TD>
<td>  </td>
<td>
<asp:label id="EndDate" Font-Size="XX-Small" Font-Names="Verdana" Text="Add: "
Runat="server" Font-Name="Verdana">End Date (mm/dd/yy):</asp:label>
</td>
<td>
<asp:TextBox id="EndDate" runat="server" Height="18px" Wrap="False" MaxLength="10" Style="TEXT-ALIGN:center"
Width="75"></asp:TextBox>
</td>
</TR>
</TABLE>

<table>

<td colSpan="3">

<asp:datagrid id="m_grid" Width="1077px" runat="server" HorizontalAlign="Center" BackColor="White"
Font-Names="Verdana" BorderStyle="None" BorderWidth="2px" BorderColor="Gray" CellPadding="3"
PageSize="20" AllowSorting="True" AutoGenerateColumns="False">
<FooterStyle ForeColor="#000066" BackColor="White"></FooterStyle>
<SelectedItemStyle Font-Bold="True" ForeColor="White" BackColor="#FFFF80"></SelectedItemStyle>
<AlternatingItemStyle BackColor="LightCyan"></AlternatingItemStyle>
<ItemStyle Font-Size="XX-Small" Font-Names="Verdana" ForeColor="#000066"></ItemStyle>
<HeaderStyle Font-Size="XX-Small" Font-Names="Verdana" Font-Bold="True" ForeColor="White" BorderStyle="Inset"
BorderColor="Silver" BackColor="SteelBlue"></HeaderStyle>
<Columns>
<asp:HyperLinkColumn Target="_blank" DataNavigateUrlField="Link" DataTextField="Number" SortExpression="Number"
HeaderText="Number">
<HeaderStyle HorizontalAlign="Center" Width="60px"></HeaderStyle>
<ItemStyle HorizontalAlign="Center"></ItemStyle>
</asp:HyperLinkColumn>

<asp:BoundColumn Visible="False" DataField="Pre" SortExpression="Pre"></asp:BoundColumn>

<asp:TemplateColumn SortExpression="Pre" HeaderText="Pre?">
<HeaderStyle HorizontalAlign="Center" Width="80px"></HeaderStyle>

<ItemTemplate>
<div>
<input id="inpHide" type="hidden" runat="server" />
<asp:DropDownList id="dd" runat="server" Width="87px" Font-Size="XX-Small" Font-Names="Verdana" Font-Bold="True" ForeColor="Black" onselectedindexchanged="dd_SelectedIndexChanged" onChange="ConfirmIt()" AutoPostBack="true" >
<asp:ListItem Value="Pending">Pending</asp:ListItem>
<asp:ListItem Value="Yes">Yes</asp:ListItem>
<asp:ListItem Value="No">No</asp:ListItem>
</asp:DropDownList>
</div>
</ItemTemplate>

</asp:TemplateColumn>
<asp:BoundColumn Visible="False" DataField="Notes" SortExpression="Notes"></asp:BoundColumn>
<asp:TemplateColumn SortExpression="Notes" HeaderText="Pre_Notes">
<HeaderStyle Wrap="True" HorizontalAlign="Center" Width="100px"></HeaderStyle>
<ItemStyle HorizontalAlign="Center"></ItemStyle>
<ItemTemplate>
<asp:TextBox id="txtNote" TextMode="MultiLine" wrap="true" Columns="30" Rows="2" runat="server" Font-Names="Verdana" Font-Size="XX-Small"></asp:TextBox>
</ItemTemplate>
</asp:TemplateColumn>
<asp:BoundColumn DataField="State" SortExpression="State" ReadOnly="True" HeaderText="State">
<HeaderStyle HorizontalAlign="Center" Width="100px"></HeaderStyle>
</asp:BoundColumn>

</tr>
</table>
</form>

<SCRIPT language="javascript">

function showWaitMessage()
{

}

//many more functions.

</SCRIPT>

</body>
</html>

My Program.ascx.cs is

namespace a.b.c
{
using System;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Text;
using System.Drawing;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Collections.Generic;
using System.Web;

/// <summary>
///
/// </summary>
public partial class Program : System.Web.UI.UserControl

{
private string tDate = string.Empty;

#region Class Variables
//strings and variables initialization
#region GUI Components
//all gui componenets..
protected System.Web.UI.WebControls.Label Label1;
protected System.Web.UI.WebControls.ImageButton btnRefresh;

#endregion
#endregion

#region Public Properties
public bool IsAdmin
{
}

public string SortExpression
{

}

//many public functions

#endregion

#region Web Form Designer generated code
override protected void OnInit(EventArgs e)
{
InitializeComponent();
base.OnInit(e);
}

/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.btnSaveChanges.Click += new System.Web.UI.ImageClickEventHandler(this.btnSaveChanges_Click);
this.btnExcel.Click += new System.Web.UI.ImageClickEventHandler(this.btnExcel_Click);
//many more
this.Load += new System.EventHandler(this.Page_Load);
// this.ddPreApproved.SelectedIndexChanged += new System.EventHandler(this.ddPreApproved_SelectedIndexChanged);
}
#endregion
#region Public Methods
//many more public method..
public void Refresh()
{
try
{

}
catch (Exception ex)
{

}
}
#endregion
#region Private Methods

//many private functions...i have just displayed mine..I have changed private to //protected..then also its not working
private void ddPreApproved_SelectedIndexChanged(object sender, EventArgs e)
{
int DiagResult = int.Parse(inpHide.Value);

if (DiagResult == 1)
{
//Do Somthing
Response.Write("You Have Selected Ok");
}
else if (DiagResult == 0)
{
//Do somthing
Response.Write("You have Selected Cancel");
}

}
private void btnSaveChanges_Click(object sender, System.Web.UI.ImageClickEventArgs e)
{

}
#endregion
}
}

Can u think of any soln for this so that hiddenfield is retrieved..Do u think there is problem in the Program.ascx..Just check it if i have put form and div correctly... And also i have not pasted all my code but only the code that is neccessary...Here the program which i am doing goes like this..If user does any changes in the drop-downlist,It should notify to the user..For that m using hiddenfield concept but its not working ..