I'm attempting to change the value of a ComboBoxTool (a drop down list) in code.  How do I do that?  I've tried the following:

ComboBoxTool a = (ComboBoxTool)(this.ultraToolbarsManager1.Tools["MyComboBox]);

a.ValueList.SelectedItem = "ThirdOption";

I've also tried a.ValueList.SelectedIndex=2;

Neither seemto change the value in the ribbon.  How do I do it?

 Thanks.

-Nick