New to .NET 2.0 user controls - Need help with public properties

I am building a custom "Yes/No" control for a survey application. The control has 2 labels (Yes/No) and two image buttons which display a graphical version of a checkbox. What I need is simple, when the user clicks on either the yes or no, the images change to reflect the new value of the control-- as in when 'Yes' is selected, the 'yes' image button url changes to the selected graphic and the 'no' image button changes to the unselected variation. Fortunately, I have that part working ok (although I'm sure there's a better way to do it). What I need help with is exposing a value property for the control so when a user selects yes or no, the value is modified accordingly. I need to programatically be able to set or get the value of the control and it will render as such. I tried doing it the way I thought would work however, the value does not persist on postback so it's always false. When I debug, clicking "Yes" set's  _value to true but when the page loads again, it's back to false. I will paste the control code and the codebehind I have now. Any help is very appreciated.

- Mike


=============== YESNOCONTROL.ASCX ========================

<asp:Table runat="server" ID="tblYesNo" CssClass="yesNoTable">
            <asp:TableRow CssClass="yesNoRow">
            <asp:TableCell CssClass="yesNoTableData">
                <asp:LinkButton ID="lnYes" OnClick="Yes_Click" CssClass="yesNoLink" ForeColor="Black" Font-Underline="false" runat="server">Yes</asp:LinkButton>
                <asp:ImageButton runat="server" OnClick="Yes_Click"  ID="imgYes" CssClass="yesNoImage" ImageUrl="~/Images/YesNo_default.jpg" Width="25" Height="20" />            
            </asp:TableCell>
            <asp:TableCell CssClass="yesNoTableData">
                    <asp:LinkButton ID="lnNo" OnClick="No_Click"  CssClass="yesNoLink" ForeColor="Black" Font-Underline="false" runat="server">No</asp:LinkButton>
                    <asp:ImageButton runat="server" OnClick="No_Click"  ID="imgNo" CssClass="yesNoImage" ImageUrl="~/Images/YesNo_selected.jpg" Width="25" Height="20" />                        
                </asp:TableCell>
            </asp:TableRow>
        </asp:Table>




=============== YESNOCONTROL.ASCX.CS ========================

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.ComponentModel;

public partial class Modules_YesNoControl : System.Web.UI.UserControl
{
   
    private bool _value = false;

    protected void Page_Load(object sender, EventArgs e)
    {

    }

    [Bindable(true),Category("Behavior"),Description("Set the default value of this control"),DefaultValue(false),Localizable(true)]
    public bool Value
    {
        get
        {
            return _value;

        }
        set
        {
            _value = value;          
        }
    }
      

    protected void Yes_Click(object sender, EventArgs e)
    {
        _value = true;
        imgYes.ImageUrl = "~/Images/YesNo_selected.jpg";
        imgNo.ImageUrl = "~/Images/YesNo_default.jpg";
       
    }

    protected void No_Click(object sender, EventArgs e)
    {
        _value = false;
        imgYes.ImageUrl = "~/Images/YesNo_default.jpg";
        imgNo.ImageUrl = "~/Images/YesNo_selected.jpg";
    }

}