Public ds As DataSet
Public da As OleDbDataAdapter
Public dt As DataTable
Dim conStr As String = "SELECT * FROM testeintrag ORDER BY SID;"
Dim conn As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data" & _
  "Source=C:\test.mdb;")
Dim cmd As New OleDbCommand(conStr, conn)
 
Dim dsNewRow As DataRow
dsNewRow = frmMain.ds.Tables("testeintrag").NewRow()
ds2NewRow.Item("Schluessel") = ???
dsNewRow.Item("SID") = ???
frmMain.ds.Tables("testeintrag").Rows.Add(dsNewRow)
frmMain.da.Update(frmMain.ds, "testeintrag")