Interface Sortable - swap and limit elements

Interface Sortable - swap and limit elements

Hi guys!
For las few hours i browse the internet for a solution for my problem:
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so...
i use jquery 1.1.2 with interface. i cant use a newer version of jquery because is not compatible with interface. also, i cant use jquery UI because i have the whole site developed with interface (so i don't need advice such "upgrade").

Ok, here is the rulls:
1) all numbers are sortable
2) 2, 3, 4 works like standard sortable
3) here is the trick: if i drag (1) over (4) for example, i want to switch (1) with (4) and viceversa. i know how to automatically resize, but i don't know how to swap items

That is one of my problem, and ANY advice is good (idea, link, ANYTHING!).


My second problem is: in an example similar to this, i want to limit 3 (or one, or X) items per column. Also, i want to have a minimum items on a column.

Again, any idea is good.
Thanks a lot!