Not able to update sql database after deleting rows

Public Class Form1
 
Dim ds As DataSet
    Dim daBookings, daASNs As SqlDataAdapter
    Dim cb As SqlCommandBuilder
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
 
        ds = New DataSet()
        Dim con As New SqlConnection()
        con.ConnectionString = "Data Source=CLIENT165\SQLEXPRESS;DataBase=c:\Visual Studio 2005\Projects\GreenVesselTally\GreenVesselTally\GreenVesselTally.mdf;uid=norge;pwd=boris;Trusted_Connection=True"
 
        daBookings = New SqlDataAdapter("SELECT * FROM Bookings", con)
        daASNs = New SqlDataAdapter("SELECT * FROM ASNs", con)
 
        daBookings.Fill(ds, "Bookings")
        daASNs.Fill(ds, "ASNs")
 
Private Sub ListView1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListView1.SelectedIndexChanged
 
        Dim Rows As Integer
 
        cb = New SqlCommandBuilder(daBookings)
        cb.GetUpdateCommand()
        cb.GetDeleteCommand()
        Rows = daBookings.Update(ds.Tables("Bookings"))
 
 
        cb = New SqlCommandBuilder(daASNs)
        cb.GetUpdateCommand()
        Rows = daASNs.Update(ds.Tables("ASNs"))