connection.Open();
for (idx = 0; idx < (obsPoints.Count); idx++)
{
   subStrings = obsPoints[idx].Split();
   queryString = "SELECT field1 FROM Ergebnisse WHERE Ort=" + subStrings[0] + "" & _
     "AND Zeit=" + subStrings[1] + ";";
   command = new OleDbCommand(queryString, connection);
   reader = command.ExecuteReader();
   reader.Read();
   result = result + Convert.ToDouble(reader[0]);
   reader.Close();
}
connection.Close();