Unable to get Checkbox ID or Checked status from Control inside a Repeater

I am converting a Classic ASP program to C#/asp.net and I don't have a lot of freedom to change displayed code because of customer requirements.

To duplicate the legacy codes appearance, i used a Repeater, like so:

<asp:Repeater ID="ParentRepeater" runat="server">
<HeaderTemplate><%= strHTML %></HeaderTemplate>
<ItemTemplate>
<tr>
<td class="fileRow colHeader">
<div class="chkbx">
<input type="checkbox"  id="chkbox" name='<%#Eval("strCheckBox")%>' value='<%#Eval("strCheckBox")%>' />
</div>
<div class="icn" style="background-image:  url('<%#val("strGraphic")%>');">&nbsp;</div>
<div class="flnm"><a href='<%# Eval("strLinkTo") %>' 
title='<%# Eval("strLinkTo") %>'><%# Eval("strFileName") %> </a>
<%# Eval("strAdditionalActions") %></div>
<div class="sz"><%# Eval("strSize") %></div>
<div class="typ"><%# Eval("FriendlyType") %></div>
<div class="mddt"><%# Eval("Modified") %> <%# Eval("strTimeZone") %></div>
</td>
</tr>
</ItemTemplate>
<FooterTemplate>
</FooterTemplate>
</asp:Repeater>

I would have liked to have used a a variable for the control ID, but ID's cant be populated at run time. I used a static ID called, "chkbx". This renders as ParentRepeater$ct101$chkbox, with the 101 incrementing for each additional CheckBox in the repeater.

I need to pull the CheckBox name (which is the file name to work with) and if it is checked (meaning its selected for deletion). I have used the following, but have not been able to retrieve control information. The 2 FindControl statement come back as null.

Looping through the Repeater item, I do see something in the results view, but its all repeater info and no control info.

                Control cb = FindControl("ParentRepeater$ct101$chkbox") as Control; // ParentRepeater$ct101$chkbox
            if (cb != null)
            {
            }


            CheckBox cbx = FindControl("ParentRepeater$ct101$chkbox") as CheckBox; // ParentRepeater$ct101$chkbox
            if (cbx != null)
            {
            }


            foreach (RepeaterItem item in ParentRepeater.Items)
            {
                if(item.ItemType == ListItemType.Item || item.ItemType == ListItemType.AlternatingItem)
                {
                    Control btn = item.FindControl("ParentRepeater$ct101$chkbox") as Control;
                }
            }

Any help would be appreciated.

Eric