Sortable_element on multiple lists

Hi all,

I have a list of users belonging to a group: (user HABTM groups)

Group 1

  • user 1
  • user 2
    Group 2
  • user 4
  • user 2
  • user 5
    Group 3
  • user 6
  • user 7

I want to enable user dragging between groups. Eg. i want to move user
6 to group 1. The users are ordered alphabetically inside a group. If
I drop a user in a group it would be ideal that it is thus placed
alphabetically (not important though).

Can this be done?