private void newFileButtonActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_newFileButtonActionPerformed
        if (evt.getSource() == newFileButton) {
            final JFileChooser fc = new JFileChooser((baseFile != null) ? baseFile.getParent() : "");
            int returnVal = fc.showOpenDialog(this);
            
            if (returnVal == JFileChooser.APPROVE_OPTION) {
                File chosenFile = fc.getSelectedFile();
                if (!chosenFile.exists()) {
                    JOptionPane.showMessageDialog(this, "File does not exist!");
                }
                if (!chosenFile.canRead()) {
                    JOptionPane.showMessageDialog(this, "Cannot read file.");
                }
                compareFile = chosenFile;
                newFileButton.setText(compareFile.getName());
            }
        }
    }//GEN-LAST:event_newFileButtonActionPerformed