private void btn_smallerActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_btn_smallerActionPerformed
        if (getFontSize() > 0) {
            setFontSize(fontSize - 2);
            
            lbl_display.setFont(new Font(lbl_display.getFont().getFamily(),
                0, getFontSize()));
        } else {
            JOptionPane.showMessageDialog(null, "Too small!",
                    "Error", JOptionPane.ERROR_MESSAGE);
        }
        
        displayCurrentFontSize();
    }//GEN-LAST:event_btn_smallerActionPerformed