private void npTreeValueChanged(javax.swing.event.TreeSelectionEvent evt) {//GEN-FIRST:event_npTreeValueChanged
        DefaultMutableTreeNode node = (DefaultMutableTreeNode) npTree.getLastSelectedPathComponent();

        if (node == null || node.getUserObject().equals("root")) {
            this.selectedNp = null;
            btnReply.setEnabled(false);
            lblSelectedNp.setText("");
            return;
        }

        NanoPostTreeItem npti = (NanoPostTreeItem) node.getUserObject();

        lblSelectedNp.setText(npti.np.toString());
        this.selectedNp = npti.np;
        btnReply.setEnabled(true);
    }//GEN-LAST:event_npTreeValueChanged