Ardi Cendols

//your method in contoller
public method(){
    if($this->input->post('id_kustomer')){
        $cutomer_id = (int) $this->input->post('id_kustomer');
        //customer data from model
        $data = $this->your_model->get_customer_data($cutomer_id);
        if($data){
            var_dump($data);
        }else{
            die('customer data not found');
        }
    }
}

//your method in model

public get_customer_data($value,$field = 'id'){
    $result = $this->db->select('nama_kustomer,no_hp,alamat')
               ->get_where('table',array($field=>$value),1)
               ->row();
    return $result ? : false;
}