Object datasource bind problem

[Kevin]

Hi my name is Kevin

can someone help me with the objectdatasource, when binding bussines objects
to it ?
i can normally bind them to a grid and detail grid but the problem remains
that when the bussiness object user that i bind in the detailgrid
holds child obbjects like and adress object, so when i update the main
object my child object location isnt passed through my insert method

i have a usercollection boud to a datadgrid, when i click it i go get the
details from it by selecting a user by id and show them in a detailsgrid
i have an itemtemplate boud o name and one bound to the
location.locationnaam, when i clinck insert user i show insert itemtemplate

i can enter a name for the user and i added a single datasource to show a
list of location objects in a dropdownlist

now when i click insert my user object is filled in, i see the name i
entered BUT,... my location object in my user object is empty

and i selected one from the dropdownlist, how can i pas the object i
selected from a different datasource to the object i am inserting in the
main object data source

method on my bl layer

public sub insertUser(User as object)

class User

mname as string
mlocation as location

Please i really need some help on this