Uncaught TypeError

by jimkennelly

HTML

<link rel="stylesheet" href="https://rawgit.com/wenzhixin/bootstrap-table/master/src/bootstrap-table.css">
<script src="https://rawgit.com/wenzhixin/bootstrap-table/master/src/bootstrap-table.js"></script>
<table id="table" data-single-select="false"  data-maintain-selected="true" data-toggle="table" data-search="true" class="table table-condensed table-hover">

  <!--Table head-->
  <thead>
    <tr>
      <th style="" data-field="state">
        <div class="th-inner "></div>
        <div class="fht-cell"></div>
      </th>
      <th style="" data-field="first_name">
        <div class="th-inner sortable both">First Name</div>
        <div class="fht-cell"></div>
      </th>
      <th style="" data-field="last_name">
        <div class="th-inner sortable both">Last Name</div>
        <div class="fht-cell"></div>
      </th>
      <th style="" data-field="title">
        <div class="th-inner sortable both">Title</div>
        <div class="fht-cell"></div>
      </th>
      <th style="" data-field="company">
        <div class="th-inner sortable both">Company</div>
        <div class="fht-cell"></div>
      </th>
      <th style="" data-field="5">
        <div class="th-inner ">Email</div>
        <div class="fht-cell"></div>
      </th>
    </tr>
  </thead>
  <!--Table head-->
  <tbody>
    <tr data-index="0">
      <td style=""><input type="checkbox" name="job[contact_ids][]" value="" id="job_contact_ids_"></td>
      <td id="1135_first_name" style=""> Gmail</td>
      <td id="1135_last_name" style="">Five</td>
      <td style=""><span class="text">Title 5</span></td>
      <td style=""><span class="text">Company 5</span></td>
      <td style=""><span id="1135_email">[email protected]</span></td>
    </tr>
    <tr data-index="1">
      <td style=""><input type="checkbox" name="job[contact_ids][]" value="" id="job_contact_ids_"></td>
      <td id="1141_first_name" style=""> Gmail</td>
      <td id="1141_last_name" style="">Four</td>
      <td style=""><span...

JavaScript

function formatCheckbox(value, row, index) {
     return '<input type="checkbox" name="job[contact_ids][]" value="' + value + '" id="job_contact_ids_' + value + '">';
   }