Script to add a label to the Comment field in a Salsa Classic petition.

petition_comment_label.html

<script type="text/javascript">
  document.addEventListener("DOMContentLoaded", function () {
      var e = document.querySelector('input[name=action_KEY]')
      if (e != null) {
        var label = document.querySelector('label[for="Comment"]'); 
        if (label != null) {
          label.innerHTML = "Comment";
        }
      }
    });
</script>