Problems populating selection box from database

Hi all,

I’ve been attempting to populate a selection box in one of the rows of my grid from a database table, i followed the tutorial here: [url]http://docs.dhtmlx.co/doku.php?id=dhtmlxconnector:select-box_columns_in_grid[/url] and my code looks like this:

$grid_conn = new GridConnector($conn, "MySQL");
 
$options_conn = new SelectOptionsConnector($conn,"MySQL");
 // render the options information with a value and a label
$options_conn->render_table("preference_level","Preference_Level","Preference_Level(value),Preference_Description(label)");
// specify a query to get the required area preferences run it an render the results in a grid
$grid_conn->set_options("Preference_Level", $options_conn);

However I keep getting the following error message:

I’ve had a similar issue before when the names given in the grid did not match those in the render_table function but I’ve checked all the names and they are correct so Im not sure what the problem is, can anyone help?

Thanks in advance.