Undoing/Recreating Changes
Use
If you have already made changes to data in the overview area, but have not yet saved them, you can use 
and 
to undo or recreate them.
Prerequisites
You have changed data but you have not yet saved.
A change (no assignment) in the detail area: You have confirmed the change with Return, or you carried out another activity after the change, chosen another tab page, for example.
Procedure
to undo the last change.The change is undone.
to recreate the last change.The change is recreated.
when you want to finally confirm your changes.