InfoPath Dev

I have built my Listbox in Design mode in Infopath Form designer. I don't have any datasource to this listbox but is a static one.i have added some 1-2 values to the listbox in design mode by right clicking and click the Add button. But my problem is I want to add 1 more value(option item) to this Listbox at runtime that too using VS.Net(C# or ...

I have an issue with Listbox.What i want to do is add a new option to an existing listbox using VS.Net (C# or VB.Net) on the click of a button. Does any one have an answre...pls its urgent!!!