Function onkeyup and overlay

When I use the onkeyup function, the table that appears to me does not overlay the video. How can I overlay the table.

I post both the html code and the javascript

function finName(ogg) {
  var name = $.trim($(ogg).val());

  if (name.length < 3) {
    return;
  }

  $.ajax({
    type: "GET",
    url: "core/main.php",
    data: "ID=getName&name=" + escape(name),
    dataType: "html",
    cache: false,
    success: function(msg) {
      $('#box').html(msg);

    },
    error: function(x, t, m) {

    }
  });
}

<div class="col-sm-5">
  <div class="input-group input-group-sm">
    <span class="input-group-addon alert-secondary chgsize1" id="basic-addon3 overlay">Name</span>
    <input onkeyup="findName(this)" type="text" name="search" size="90" class="form-control" placeholder="Search">

    <div id='box'>
      <!-- box  -->
    </div>
  </div>
</div>