Building a checkbox list using an asp placeholder html grid in ASP.NET C#

Hopefully there is a solution for this. What i have is somewhat limiting. First of all i'm using a master page in my source which is preventing me from inserting javascript functions in to my aspx body. When i try i get the error "This page contains markup that is not valid when attached to a master page" as my page is defined as:

<%@ Page Title="" Language="C#" MasterPageFile="~/nav/HorizMenu.Master" AutoEventWireup="true" CodeFile="TEST.aspx.cs" Inherits="WebForms_TEST" %>
<%@ MasterType virtualpath="~/nav/HorizMenu.Master" %>

My next challenge is that i am populating a table using the asp placeholder control:

aspx:

<div class="row">
                                <div class="col s12">
                                    <ul class="tabs">
                                        <li class="tab"><a href="#Total">Total (
                                            <asp:PlaceHolder ID="DBTotalCount" runat="server"></asp:PlaceHolder> 
                                            <!--Records #-->)</a></li>
                                        <li class="tab"><a href="#Pending">Pending (
                                            <asp:PlaceHolder ID="DBPendingCount" runat="server"></asp:PlaceHolder> 
                                            )</a></li>
                                        <li class="tab"><a href="#Approved">Approved (
                                            <asp:PlaceHolder ID="DBApprovedCount" runat="server"></asp:PlaceHolder> 
                                            )</a></li>
                                    </ul>
                                </div>
                            </div>

cs:

//Set up Total column
                for (var i = 0; i < ds.Tables["tblTotal"].Rows.Count; i++)
                {
                    //force empty string to prevent null errors
                    var rowName = string.IsNullOrEmpty(ds.Tables["tblTotal"].Rows[i]["Name"].ToString()) ? "" : ds.Tables["tblTotal"].Rows[i]["Name"];
                    var rowAddress = string.IsNullOrEmpty(ds.Tables["tblTotal"].Rows[i]["Address"].ToString()) ? "" : ds.Tables["tblTotal"].Rows[i]["Address"];
                    var rowId = string.IsNullOrEmpty(ds.Tables["tblTotal"].Rows[i]["ID"].ToString()) ? "" : ds.Tables["tblTotal"].Rows[i]["ID"];
                    var rowGuid = string.IsNullOrEmpty(ds.Tables["tblTotal"].Rows[i]["CustGUID"].ToString()) ? "" : ds.Tables["tblTotal"].Rows[i]["CustGUID"];
                    var rowDob = string.IsNullOrEmpty(ds.Tables["tblTotal"].Rows[i]["DateOfBirth"].ToString()) ? "" : ds.Tables["tblTotal"].Rows[i]["DateOfBirth"];
                    var rowUrl = startURL(Request["isadmin"] != "0", rowGuid.ToString());

                    //write out this row
                    htmlTotal.Append("<tr>");
                    htmlTotal.Append(@"<td>");
                    htmlTotal.Append(@"<a href=" + rowUrl + "> " + rowName + @"</a>");
                    htmlTotal.Append(@"</td>");
                    htmlTotal.Append(@"<td>");
                    htmlTotal.Append(@"<a href=" + rowUrl + "> " + rowAddress + @"</a>");
                    htmlTotal.Append(@"</td>");
                    htmlTotal.Append(@"<td>");
                    htmlTotal.Append(@"<a href=" + rowUrl + "> " + rowId + @"</a>");
                    htmlTotal.Append(@"</td>");
                    htmlTotal.Append(@"<td>");
                    htmlTotal.Append(@"<a href=" + rowUrl + "> " + rowDob + @"</a>");
                    htmlTotal.Append(@"</td>");
                    htmlTotal.Append(@"<td>");
                    htmlTotal.Append(@"<input type=""checkbox"" Enabled=""true"" name=""chkTotal" + i + @""" value=""" + "VAL" + i + @""">"); //email check box
                    htmlTotal.Append(@"</td>");
                    htmlTotal.Append("</tr>");
                }
            }
            else
            {
                htmlTotal.Append("<tr>");
                htmlTotal.Append("<td align='center' colspan='6'>No Results Found</td>");
                htmlTotal.Append("</tr>");
                htmlTotal.Append("</table>");
                htmlTotalCount.Append("0");
            }

            //link the page dynamic control back to the html string builder code
            DBTotal.Controls.Add(new Literal { Text = htmlTotal.ToString() });
            DBTotalCount.Controls.Add(new Literal { Text = totalRecords.ToString() });
            htmlTotalCount.Append(" of " + totalRecords + " results");
            DBTotalCount2.Controls.Add(new Literal { Text = htmlTotalCount.ToString() });
            TotalPagination.Controls.Add(new Literal { Text = htmlTotalPagination.ToString() });

you can see above where i started adding in the check boxes.

My challenge is that i need to add a check box at the trail of each row loop that i can tick, and when i click the asp button control i can return a value specified by that given row for each check box that the user has checked.

Given that my master page is preventing me from using JS, and that i'm using a placeholder control to construct the page HTML on the fly, any idea if what i need to accomplish here is possible, and if so, how?

Thank you for your help!