gridview, objectdatasource

I have few classes in my business layer like:

Country:
CountryId (int)
CountryName (string)

CountryManager:
GetAllCountry
AddCountry
RemoveCountry
UpdateCountry

State:
StateId (int)
StateName (string)
StateCountry (country)

StateManager:
GetAllState
AddState
RemoveState
UpdateState


I am using a Gridview control to maintain list the states on AdminState
page. There are template fields for the StateName and CountryId
columns.

I have an ObjectDataSource defined as:

<asp:ObjectDataSource ID="StateDataSource" runat="server"
TypeName="MyBusinessLayer.StateManager"
DataObjectTypeName="MyBusinessLayer.State"
SelectMethod="GetAllState"
DeleteMethod="RemoveState"
UpdateMethod="UpdateState" >
</asp:ObjectDataSource>

Since the CountryId property is not defined on the State object,
gridview throws the error:

DataBinding: 'MyBusinessLayer.State' does not contain a property with
the name 'CountryId'

How can I bind the controls in the gridview template columns to
properties in my business object that point to other business objects?

Thanks in advance!

family