List box question: 9.01

I have a custom screen that works nicely on 9.00.  I populate a custom list with Supervisor code and Name.

ListVal.setAttribute("text",Supervisor_code);
ListVal.setAttribute("tran",Supervosr_code);
ListVal.setAttribute("disp",Supervisor_name); 

Upgraded to 9.01 and still works, except the way the list options are displayed have changed.

On 9.0, it used to display just the Supervisor Names (which is what users know and want to see).
On 9.01, it shows Supervise Code, Supervor Name.Looks like it shows whatever is populated in the "tran" field first. This is confusing to the the users. Looks like this is a required field, so I cannot leave it blank.

What options do I have? Thanks.