To make values in the InfoPath Drop down Blank

To delete filled drop down values blank we have to write following mentioned code in the link

and have to add following code:

XMLDom.SelectSingleNode("/my:myFields/my:CustomersListGroup/my:Displayname", NamespaceManager).SetValue("");

XMLDom.SelectSingleNode("/my:myFields/my:CustomersListGroup/my:Value", NamespaceManager).SetValue("");

Drop Down Xpath :

XMLDom.SelectSingleNode("/my:myFields/my:AccountInformationSection/my:DDL", NamespaceManager).SetValue("");