How to keep a ComboBox from having a selected item.

I've successfully bound a combobox to datatable, however, even afer I bind the combo and then set the selectedindex to -1, it still resets itself so the first item (selectedindex 0) is selected. Any thoughts how I can turn off this behavior? Thanks, Erik

While I haven't found a solution to my problem, I have found some information on the net that indicates this isn't possible. A post from an individual claiming to be from Microsoft, basically said the only way to accomplish this was to ensure the first item (index 0) is either null or an empty string and handle that accordingly. If anyone else has found another solution, I'd love to hear it. Thanks, Erik