[RESOLVED] Error with add new row to table VBE2005-SQL server

[wizkid]

I am trying to add new row to the table
but i can't
error is object reference not set to an instance of an object

code:

Dim cust_det_ds As New DataSet
  Dim cust_det_da As New OleDb.OleDbDataAdapter
  If count_custdetails2 = 0 Then 'if the customer is not in cust_details2 table
      Dim cb1 As New OleDb.OleDbCommandBuilder(cust_det_da)
   Dim dsNewRow As DataRow
      dsNewRow = cust_det_ds.Tables("cust_details2").NewRow()
      dsNewRow.Item("Account_no") = txtCustNo.Text
 dsNewRow.Item("Title") = txtTitle.Text
    dsNewRow.Item("Initial") = txtInitial.Text
    dsNewRow.Item("Surname") = txtSurname.Text
      dsNewRow.Item("HouseName") = txtHname.Text
     dsNewRow.Item("Address1") = txtAdd1.Text
       dsNewRow.Item("Address2") = txtAdd2.Text
            dsNewRow.Item("Address3") = txtAdd3.Text
              dsNewRow.Item("Address4") = txtAdd4.Text
                 dsNewRow.Item("Address5") = txtAdd5.Text
       dsNewRow.Item("Postcode") = txtPostcode.Text
       cust_det_ds.Tables("cust_details2").Rows.Add(dsNewRow)
    cust_det_da.Update(cust_det_ds, "cust_details2")
 Else
  End If

cust_det_ds.Tables("cust_details2").NewRow() error is in this line
Any idea?
thanks