InfoPath Dev

 I am creating the infopath form from the list content type. The content type has site columns which have choice fields.The infopath form shows these choice fields in multiselect list box at design time.

I am trying to delete these items using .DeleteSelf() method but its not getting deleted. It only makes it uncheck. If i add an item using .AppendChild() dynamically then its getting deleted using .DeleteSelf() method. But i want to remove all these items showing in design time. Any help would be highly appreciated.

So I understand your scenario correctly, you want to remove the choices from the MSLB control completely and not just uncheck them?  If that's the case, then you need to populate your entries for the MSLB from within the form and then you can use code to remove the nodes which will then remove the values from the MSLB control.