Form validation error

EDIT: I found out what error I had. I named input and submit button same. Beginner mistake. Sorry. Can be deleted.

Hi,

I have a function which shows and validate input, but I have a problem with variables after submit ($_POST / $this->input->post() is empty !!!)

This is my function. I have all libraries used inside of this function activated

This is my function. All the time I get the required error. Has anyone an idea ?

PHP Code:

// Check if we have any request
        if($this->input->post()){
            // Set delimiters
            $this->form_validation->set_error_delimiters(
                '<div class="error_prefix"><i class="fa fa-info-circle"></i> ',
                '</div>'
            );

            $this
                ->form_validation
                // Validate 'Event code'
                ->set_rules(
                    'event_code',
                    'lang:event_code',
                    'required|trim|min_length[4]|max_length[25]|callback_event_exists',
                    [
                        'required'               => lang('event_code_required'),
                        'min_length'             => lang('event_code_min_length'),
                        'max_length'             => lang('event_code_max_length'),
                        'event_exists'           => lang('event_code_exists')
                    ]
                );

            // Check if our form looks good
            if(false !== $this->form_validation->run()){
                redirect(base_url('validate/' . $this->input->post('event_code')));
            }
        }

        // Variables
        $this->data['title']                = 'Mainpage :: ' . $this->data['raw_title'];

        // Get current language flag
        $getCurrentLangFlag = $this->language->findBy(['lang_abbr'=>$this->session->userdata('lang')])->row();

        $this->data['current_lang_flag']    = '<img src="' . base_url('public/images/flags/' . strtolower($getCurrentLangFlag->lang_flag)) . '" />';
        $this->data['languages']            = $this->language->findAllBy(['lang_abbr !='=>$this->session->userdata('lang')]);

        // Views
        $this->load->view('main_page', $this->data);