jQuery sortable with table cells in a column

I need to have cells in a particular column of a table sortable.

http://jsbin.com/ilodi4

The problem is that t开发者_StackOverflowhe current code makes the whole row sortable instead of just make the cells sortable. Cells for a given column should be vertically sortable and only in their particular column.

Is there a way to assign a unique class to a table column through jQuery perhaps?