Work with result in controller

[eluser]MaxEisley[/eluser]
It doesnt work:

Code:

$customer = $this->data_model->checkcustomer($this->input->post('Phone'), $this->input->post('Email'), $this->input->post('FirstN'), $this->input->post('SecondN'));

if($customer->zakaznikID == '') {
              $id_customer = $this->data_model->createcustomer($this->input->post('Phone'), $this->input->post('Email'), $this->input->post('FirstN'), $this->input->post('SecondN'), $id_address);
        }
        
        else {
          $id_customer = $customer->zakaznikID;
        }

It still writes Trying to get property of non-object
on line: if($customer->zakaznikID == '') {