Error on trying to join tables

Hi all,

Need help, I've tried a lot of things but it doesn't work.
An image is better to understand, here my two tables
http://www.hostingpics.net/viewer.php?id...121741.png

So for a simple example, I would like to get all columns from 'client' + column 'name' from 'contact'


My actual function is :

PHP Code:

public function get_client($client_id)
      {

            $this->db->where('client_id', $client_id);
            $query = $this->db->get('client');
            if($query->num_rows()!==0)
            {
                  return $query->result();
            }
            else
            {
                  return FALSE;
            }
      } 


This function works and I would like to add the column 'name'

I tear my hair I will not have any more :-)