what is wrong with my binding?

[siomai]

hi!

I've been trying to debug this problem by myself but I'm running out of time figuring it out... what I'm trying to do is I want to bind the textboxes to different fields in my table...sounds simple right? Well, I thought so too. Take a look at my code...

Private Sub btnFind_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnFind.Click
         Try
            ds.Clear()
            daDoc.Fill(ds, "QuoteDoc")
            daTran.Fill(ds, "QuoteTran")
            ds.Relations.Add("DocTran", ds.Tables!QuoteDoc.Columns!Reference, ds.Tables!QuoteTran.Columns!Reference)
 
            txtRef.DataBindings.Add("Text", ds.Tables!QuoteDoc, "Reference")
            dtpQuote.DataBindings.Add("Text", ds.Tables!QuoteDoc, "QuoteDate")
            cmbTerms.DataBindings.Add("Text", ds.Tables!QuoteDoc, "TermsID")
            txtCustomer.DataBindings.Add("Text", ds.Tables!QuoteDoc, "CustomerID")
            txtdiscount.DataBindings.Add("Text", ds, "QuoteDoc.Discount")
            txtdiscount.DataBindings.Add("Text", ds.Tables!QuoteDoc, "Discount") \\when I inserted this code, I get an error
            txtspldiscount.DataBindings.Add("Text", ds.Tables!QuoteDoc, "SplDiscount") \\This line also produced the error
            txtgrand.DataBindings.Add("Text", ds.Tables!QuoteDoc, "QuoteTotal")
            DataGrid1.DataSource = ds.Tables!QuoteDoc
            DataGrid1.DataMember = "DocTran"
            cm = CType(Me.BindingContext(ds.Tables!QuoteDoc), CurrencyManager)
        Catch ex As Exception
            MsgBox(ex.Message, MsgBoxStyle.OKOnly, "Error")
        End Try
        btnFirst.Enabled = True
        btnnext.Enabled = True
        btnprevious.Enabled = True
        btnnext.Enabled = True
        btnlast.Enabled = True

I'm completely confused why I can't bind the two textboxes. Please help! Whenever I click on the Find button this is the error I get...

"Data cannot be read from a Datagrid which is not bound to a DataTable."