Custom drop down field ?

Hi there, this is my first thread in the forum.
I searched quite a long time for same topics like this one, but I still cannot get the solution yet.

Here is my table structure:

staff
-------------------------
| staff_ID|Hi there, this is my first thread in the forum.
I searched quite a long time for same topics like this one, but I still cannot get the solution yet.

Here is my table structure:

staff
-------------------------
| staff_ID |
|position_ID |
---------------------------

staff_car
----------------------
| s_ID |
| c_ID |
----------------------

I try to set a custom drop down field by :

$result = $this->db->query("Select * from staff where Position_ID != 3");

		foreach($result->result() as $row) :

		$string= array($row->Staff_ID => $row->Staff_ID.' '.$row->Staff_FirstName.' '.$row->Staff_SurName);

	 $crud->field_type('S_ID','dropdown',$string);

		 endforeach;

The query on it own is fine and it returns the results I want. But in the CRUD field, it own shows up with the last record.
Therefore I wonder where is the problem? Why is it not show up as an array ?

And I also have a second question, I added an action, it appear with the custom icon, but there is no text next to it, so do edit and delect.
How can I slove this ?

luis1992