public function customers_management()
{
$this->config->load('grocery_crud');
$this->config->set_item('grocery_crud_dialog_forms',true);
$this->config->set_item('grocery_crud_dialog_color','green darken-4');
$this->config->set_item('grocery_crud_dialog_text_color','white');
$crud = new grocery_CRUD();
$crud->set_theme('materializecss'); // magic code
$crud->set_table('customers');
$crud->columns('customerName','contactLastName','phone','city','country','salesRepEmployeeNumber','creditLimit');
$crud->display_as('salesRepEmployeeNumber','from Employeer')
->display_as('customerName','Name')
->display_as('contactLastName','Last Name');
$crud->set_subject('Customer');
$crud->set_relation('salesRepEmployeeNumber','employees','lastName');
$output = $crud->render();
$this->_example_output($output);
}