SuchText = List1.Text '.SelectedValue
  SQL_Text = "select * from ADREVA where schluessel=?"
  Dim ConnString As String = "Provider=Microsoft.JET.OLEDB.4.0;data source=" + _
    MStr_DatenbankName
 
  Dim myConn As New OleDbConnection(ConnString)
  Dim myCmd As New OleDbCommand( SQL_Text, myConn )
  myCmd.Parameter.AddWithValue("@Schluessel",LStr_SuchText )
  Try
    myConn.Open()
    Dim myReader As OleDbDataReader= MyOleDbCommand.ExecuteReader
    If myReader.Read Then
      GT_Adressen_Daten.nr = Val(myReader.Item("nr"))
      ...
      If  NOT myReader.IsDBNull ( myReader.GetOrdinal("bemerkung") ) Then
        GT_Adressen_Daten.bemerkung = (myReader.Item("bemerkung"))
      End If
.
.
.
    End If
  Catch ex As Exception
        MyDataReader.Close()
  Finally
    myConn.Close()
  End Try