Dropdownlist - how to use relations

[Ravi]

I am trying to represent master-detail records from a database
The general logic will be populating the first dropdownlist with the master records and on change of the first dropdownlis
getting the selectedindex and querying the database and populating the childrecords in the second dropdownlist

But my question is how the same can be acheieved by using "Relations"

The following code fragment i tried, but i have no idea how to proceed

Thanks in advanc
Ravichandra

Dim myconn As Strin
Dim oledataadapt As New OleDbDataAdapte
Dim oledataadapt1 As New OleDbDataAdapte
Dim ds As New DataSe
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Loa
'Put user code to initialize the page her

myconn = "Provider=MSDAORA;User ID=x;Password=x;Data Source=xxx;
oledataadapt = New OleDbDataAdapter("Select Organization_id from bengine.cb_organization", myconn
oledataadapt.Fill(ds, "Sector"

oledataadapt1 = New OleDbDataAdapter("Select Superbu_id, organization_id from bengine.cb_super_businessunit", myconn
oledataadapt1.Fill(ds, "SBU"
ds.Relations.Add("Sec_sbu", ds.Tables("Sector").Columns("Organization_id"),
ds.Tables("SBU").Columns("Organization_id")
If Not IsPostBack The
DropDownList1.DataSource = ds.Tables(0).DefaultVie
DropDownList2.DataSource = ds.Tables(1).DefaultVie
DropDownList1.DataMember = "Organization_id
DropDownList2.DataMember = "superbu_id
DropDownList1.DataTextField = "Organization_id
DropDownList1.DataValueField = "Organization_id
DropDownList2.DataTextField = "superbu_id
DropDownList2.DataValueField = "superbu_id
DropDownList1.DataBind(
DropDownList2.DataBind(
End I
End Su

Private Sub DropDownList1_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles DropDownList1.SelectedIndexChange
Dim i As Intege
i = DropDownList1.SelectedInde
DropDownList2.DataSource = ds.Tables(0).Rows(i).GetChildRows("Sec_sbu"
DropDownList2.DataTextField = "superbu_id
DropDownList2.DataValueField = "superbu_id
DropDownList1.DataBind(
DropDownList2.DataBind(
End Su