Undo Functionality DHTMLX

Someone please help me with how i am supposed to undo or redo a user function in dhtmlx…e.g

  1. when a user types in the form he or she is able to cancel
  2. when a user checks on a grid,can cancel and go to the previous selection

Grid has extension which allows to use undo|redo functionality

docs.dhtmlx.com/doku.php?id=dhtmlxgrid:undo