 MENU THAT IS STORED IN A MENU_MODAL.HTML FILE-->
    <div id="modal_menu_insertion"></div>
    <script>
      $(function () {
        $("#modal_menu_insertion").load("../html_chunk/menu_modal.html");
      });
    </script>

    <!-- Header -->
    <header class="masthead">
      <div class="textlanding">
        <h1>Line plot with dropdown to select group in d3.js</h1>
        <hr class="short_hr" />
        <br />
        <ul class="list-inline social-buttons">
          <li class="list-inline-item">
   