Not sure, but there's an error in your code. This:
echo_'<option>'.$result[Bezeichnung].'</option>';
Should be
echo_'<option>'.$result['Bezeichnung'].'</option>';
In addition to that, doesn't mysql_fetch_array() need to have a parameter indicating the type of array it needs to grab, like MYSQL_ASSOC in this case?
The comment isn't gonna act like a comment because it is in an echo().
🙂