Not Working out calculation database

HI

i have a access database which i input vaules from vb express the code is

Private Sub Table1BindingNavigatorSaveItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Table1BindingNavigatorSaveItem.Click

Dim Cost As Double = CDbl(CostTextBox.Text)

' CostTextBox.Text = (Format("C"))

Dim qtr As Integer = CInt(QtrTextBox.Text)

Dim del As Double = CDbl(Del_ChargeTextBox.Text)

Dim Vat As Double = (Cost * qtr + del) * 0.175

Dim total As Double = (Cost * qtr + del) * 1.175

Me.Validate()

Me.Table1BindingSource.EndEdit()

Me.Table1TableAdapter.Update(Me.OrderingDataSet.Table1)

on screen it works out the total which is great but for some reason when i view the database the total field is blank but to me its working i am now at a lost

Cheers

J