>I don't have a control data source. I used Addlistitem to populate the listbox.
>I see no way to add both columns to the other side because the addlistitem
>requires the index number before the column number.
>
>Thanks..

Is the receiving listbox .Sorted property set to .t.? If so, try something like this:

nNextListNo = this.listcount + 1
this.addlistitem("Column 1 Value", nNextListNo, 1)
this.addlistitem("Column 2 Value", nNextListNo, 2)
etc...

The item should be automatically sorted.

If the listbox is not sorted, you have to determine where you want the new item to appear in the list. It's a bit trickier. I don't know what would happen if you assigned the same Index number to two different items. They may display next to each other, but probably not.