public void importFunctions() {
		File f = Tools.showOpenDialog("Importer");
		if (f != null) {
			String ext = f.getName().substring(f.getName().length() - 3,
					f.getName().length());
			if (ext.compareTo("txt") != 0)
				JOptionPane.showMessageDialog(
						null,
						Tools.getLocalizedString("ERROR_IMPORT") + " "
								+ f.getName() + " "
								+ Tools.getLocalizedString("ERROR_IMPORT2"),
						Tools.getLocalizedString("ERROR"),
						JOptionPane.ERROR_MESSAGE);

			else {
				String functions = "";
				try {
					BufferedReader br = new BufferedReader(new FileReader(f));
					String line = br.readLine();
					while (line != null) {
						functions += line + ";";
						line = br.readLine();
					}
					isChanged = false;
					br.close();
					functions = functions.substring(0, functions.length() - 1);

				} catch (FileNotFoundException e) {
					System.err.println(e.getMessage());
				} catch (IOException e) {
					System.err.println(e.getMessage());
				} catch (Exception e) {
					System.err.println(e.getMessage());
				}

				if (functions.length() != 0) {
					program.getMainPanel().getTextField().setText(functions);
					simplify(SolutionType.DETAILLED_SOLUTION);
				} else {
					JOptionPane
							.showMessageDialog(
									null,
									Tools.getLocalizedString("ERROR_IMPORT")
											+ " "
											+ f.getName()
											+ " "
											+ Tools.getLocalizedString("ERROR_IMPORT3"),
									Tools.getLocalizedString("ERROR"),
									JOptionPane.ERROR_MESSAGE);
				}
			}
		}
	}