Once you find the highest value, you can remove that value from your ds_map, run the script again, which will return the new highest value (which would be the second highest), and rinse and repeat. That's one 'simple' way of getting it done.
Alright, well, I could easily copy and paste this and be done after a bit of tweaking, but I won't be done until I understand it fully. First off, what's the difference between a "list" and a "map"? Furthermore, I don't know of the "for" function, nor the I's you put after that. I'd like to understand these things, thanks for the help.