Add capabilities to drop down lists. My thoughts on how to implement, just a suggestion.
radio buttons (or whatever) for three sorting choices:
Ascending (letters A to Z; numbers smallest to largest to)
Descending ( letters Z to A; numbers largest to smallest)
a combo box style drop down
a drop down with 2 columns: one column with the value to be inserted into the field and one column with a description of the drop down item.
the "ultimate" drop down
create a drop down and select sorting (in Customization).
On the form, type in "new" drop down values which automatically add to the drop down and sorted as selected. This would be a combo style drop down.