Database cannot Update unable to find TableMapping

[gobblegob]

Hello All,
I am getting an error trying to update datagridview1 , what i am trying to do is search for an item (BarCode.text) and then display the results to datagridview1 but i just cannot manage to do it , please help me i have been trying for days :(

here is what i have this code is extremely crappy as i have read lots of tutorials and searches....

Imports System.Data.OleDb
 
 
Public Class ServiceCompletedForm
    Dim connStr As String
    Dim conn As New OleDbConnection
    Dim da As New OleDbDataAdapter
    Dim ds As DataSet = New DataSet
    Dim cnString As String
    Dim sqlQRY As String
    Dim myCmd As New OleDbCommand
    Dim myDR As OleDbDataReader
    Dim strSQL As String
 
 
    Private Sub ServiceCompletedForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
 
        DataGridView1.Columns.Add("BarCode", "Item Barcode")
    End Sub
 
    Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click
        da.Update(ds, "ServiceCompleted")
    End Sub
 
    Private Sub SearchBarcodeDELETE()
        cnString = "Provider=Microsoft.Jet.OLEDB.4.0;Persist Security Info=False;Data Source=..\data\Northwind.mdb"
        sqlQRY = "SELECT * FROM ServiceCompleted " 'WHERE BarCode'"
        conn = New OleDbConnection(cnString)
        Try
            conn.Open()
            da = New OleDbDataAdapter(sqlQRY, conn)
            'create command builder
            Dim cb As OleDbCommandBuilder = New OleDbCommandBuilder(da)
            'fill dataset
            da.Fill(ds, "ServiceCompleted")
            DataGridView1.DataSource = ds
            DataGridView1.DataMember = "ServiceCompleted"
        Catch ex As OleDbException
            MsgBox(ex.ToString)
        Finally
            ' Close connection
            conn.Close()
        End Try
    End Sub
    Function IsConnected() As Boolean
        Try
            'Checks first if already connected to database,if connected, it will be disconnected.
            If conn.State = ConnectionState.Open Then conn.Close()
            conn.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Persist Security Info=False;Data Source=..\data\Northwind.mdb"
            conn.Open()
            IsConnected = True
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
    End Function
    Public Function KeyAscii(ByVal UserKeyArgument As KeyPressEventArgs) As Short
        KeyAscii = Asc(UserKeyArgument.KeyChar)
 
    End Function
    Sub SearchBarcode(ByVal Barcode As String)
        Try
            If IsConnected() = True Then
                'Queries to database
 
                strSQL = "SELECT * FROM servicecompleted WHERE BarCode = '" + Barcode + "' "
 
                myCmd.CommandText = strSQL
                myCmd.Connection = conn
                da.SelectCommand = myCmd
                myDR = myCmd.ExecuteReader()
 
                'Display results to table
 
                While (myDR.Read())
 
                    DataGridView1.Rows.Add(myDR("BarCode")) ', myDR("Description"), myDR("Location"), myDR("Building_Number"), myDR("Test_Tag_Interval"))
 
                End While
            End If
        Catch ex As Exception
            MsgBox(ex.Message, , "SearchBarcode")
        End Try
        conn.Close()
    End Sub
 
    Private Sub txtBarcode_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles txtBarcode.KeyPress
        If Me.KeyAscii(e) = 13 Then
            If IsConnected() = True Then Call SearchBarcode(txtBarcode.Text)
            e.Handled = True
        End If
    End Sub
 
 
End Class