deleting out ouf a database with checkboxes

Question

I have a web page showing all the photos with locations held in a database with a checkbox next to each 1 and a button at the bottom. I am trying to get it so when the user clicks the button all the checkboxes that are checked delete the photos location held in the databse and photo from the server. But with the code below it never gets in to the if statement " if (PhotoChk.Checked == true)" beacuse for some reason no matter wot checkboxes are checked it never detects them as being checked. If I change the if (PhotoChk.Checked == true) to if (PhotoChk.Checked == false) it deletes all the photos reqardless of wots boxes are checked. Can any help me I am a noob to this and can't work out why its not workeing cheers

my aspx file
<%@ Page Language="C#" MasterPageFile="~/fowlmereplaygroup.master" AutoEventWireup="true" CodeFile="AdminPhoto.aspx.cs" Inherits="AdminPhoto" Title="Untitled Page" %>
<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
    <h1>Photo Admin</h1>
    <asp:Label ID="dbErrorMessage" runat="server" />
    <asp:GridView ID="PhotoView" runat="server" AutoGenerateColumns="False">
        <Columns>
          <asp:TemplateField Visible="false">
            <ItemTemplate>
                <asp:Label ID="PhotoIDlbl" Text='<%# Eval("PhotoID") %>' runat="server" />
            </ItemTemplate>
          </asp:TemplateField>
          <asp:TemplateField Visible="false">
            <ItemTemplate>
                <asp:Label ID="PhotoLocationlbl" Text='<%# Eval("PhotoLocation") %>' runat="server" />
            </ItemTemplate>
          </asp:TemplateField>
          <asp:TemplateField HeaderText="Photo">
            <ItemTemplate>
                <asp:Image ID="Image1" ImageUrl='<%# Eval("PhotoLocation")  %>' runat="server" />
            </ItemTemplate>
          </asp:TemplateField>
          <asp:TemplateField HeaderText="Delete">
            <ItemTemplate>
                <asp:CheckBox ID="PhotoChk" runat="server" />
            </ItemTemplate>
          </asp:TemplateField>
        </Columns>
    </asp:GridView>
    <asp:Button ID="Deletebtn" runat="server" Text="Delete" OnClick="Deletebtn_Click" />
</asp:Content>

my aspx.cs file
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.Data.SqlClient;

public partial class AdminPhoto : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        // Define data objects
        SqlConnection conn;
        SqlCommand comm;
        SqlDataReader reader;

        // Read the connection string from Web.Config
        string connectionString = ConfigurationManager.ConnectionStrings["fowlmereplaygroup"].ConnectionString;

        // Initialise connection
        conn = new SqlConnection(connectionString);

        // Create Command
        comm = new SqlCommand("SELECT PhotoID, PhotoLocation FROM Photos", conn);

        // Enclose database code in try catch finally
        try
        {
            // Open the connection
            conn.Open();

            // Execute the command
            reader = comm.ExecuteReader();

            // Fill the grid with data
            PhotoView.DataSource = reader;
            PhotoView.DataBind();

            // Close the reader
            reader.Close();
        }
        finally
        {
            // Close the connectionString
            conn.Close();
        }
    }

    protected void Deletebtn_Click(object sender, EventArgs e)
    {
        for (int vLoop = 13; vLoop < PhotoView.Rows.Count; vLoop++)
        {
            CheckBox PhotoChk = (CheckBox)PhotoView.Rows[vLoop].FindControl("PhotoChk");
            if (PhotoChk.Checked == true)
            {
                Label PhotoIDlbl = (Label)PhotoView.Rows[vLoop].FindControl("PhotoIDlbl");

                int PhotoID = Convert.ToInt32(PhotoIDlbl.Text);

                // using the PhotoID, delete that record. by using sqlcommand and its executenonquery() method

                // Define data objects
                SqlConnection conn;
                SqlCommand comm;

                // Read the connection string from Web.Config
                string connectionString = ConfigurationManager.ConnectionStrings["fowlmereplaygroup"].ConnectionString;

                // Initialise connection
                conn = new SqlConnection(connectionString);

                // Create Command
                comm = new SqlCommand("DELETE FROM Photos WHERE PhotoID=@PhotoID", conn);

                // Add Comand Parameters
                comm.Parameters.Add("@PhotoID", System.Data.SqlDbType.Int);
                comm.Parameters["@PhotoID"].Value = PhotoIDlbl.Text;

                try
                {
                    // Open the connection
                    conn.Open();

                    // Execute the command
                    comm.ExecuteNonQuery();
                }
                catch
                {
                    // Display error message
                    dbErrorMessage.Text = "Error deleting event";
                }
                finally
                {
                    // Close the connection
                    conn.Close();
                }
                Label PhotoLocationlbl = (Label)PhotoView.Rows[vLoop].FindControl("PhotoLocationlbl");

                string filepath = PhotoLocationlbl.Text;

               System.IO.File.Delete(filepath);

            }
        }
    }
}