This sample database show various ways of sorting a listbox by clicking on the header of each column.

The Simple form shows how to place buttons at the top of listbox columns to sort the listbox based on that column. The sort is only Ascending.

The Complex form does the same as the Simple form, but allows the user to sort Ascending or Descending. It works very similarly to the Message List in Outlook where you can sort Ascending or Descending by clicking on the column headers.