public ArrayList<Employee> searchEmployee(String firstname, String familyname) {
        String newFirstname = firstname.toLowerCase();
        String newFamilyname = familyname.toLowerCase();

        ArrayList<Employee> result = new ArrayList<Employee>();
        for (Employee tmpEmployee : employees.values()) {
            String tmpFirstname = tmpEmployee.getFirstName().toLowerCase();
            String tmpFamilyname = tmpEmployee.getFamilyName().toLowerCase();
            if (!newFirstname.isEmpty()) {
                if (tmpFirstname.contains(newFirstname) && (newFamilyname.isEmpty() || tmpFamilyname.contains(newFamilyname))) {
                    result.add(tmpEmployee);
                }
            } else if (!newFamilyname.isEmpty()) {
                if (tmpFamilyname.contains(newFamilyname)) {
                    result.add(tmpEmployee);
                }
            } else {
                return getEmployees();
            }
        }
        return sort(result);
    }