public void valueChanged(ListSelectionEvent lse) {
        selectedAccount = null;
        if (!lse.getValueIsAdjusting() && lijst.getSelectedIndex() != -1) {
            selectedAccount = lijst.getSelectedValue();
        }
        boolean accountSelected = (selectedAccount != null);
        accountDetails.setEnabled(accountSelected);
        debet.setEnabled(accountSelected);
        credit.setEnabled(accountSelected);
    }