how to add datasource as a sub node in xml file

Question

Hi I have a few textbox entries that i have written to an xml file and now I have to add a datasource as its child node. Any ideas on how to achieve this. I did try WriteXml method for datasource but this does not write to the file as a child node. This is what I am trying to do The query's name and age are textbox entries and the Criteria is a part of the dataset. So i am trying to insert as child node to Any ideas will be greatly appreicated Thanks in advance