redmine/app/views/journals/edit.js.erb

$("#journal-<%= @journal.id %>-notes").hide();

if ($("form#journal-<%= @journal.id %>-form").length > 0) {
  // journal edit form already loaded
  $("#journal-<%= @journal.id %>-form").show();
} else {
  $("#journal-<%= @journal.id %>-notes").after('<%= escape_javascript(render :partial => 'notes_form') %>');
}