Yes, I mean that "a" is lower than "A, "A" is lower than "B", etc.
For example, I have 5 records in my database Cities
(1) New York
(2) Paris
(3) Brussels
(4) London
(5) San Francisco
The Minimum value in my database should be "Brussels" and the Maximum value should be "San Francisco".. but I can write the script/field because it is not a numeric field