UNDO - REDO
UNDO and U will undo the last thing or group of things that you did. REDO will redo a command that was previously UNDONE.
You can access the Undo command by:
typing undo at a Command: prompt,
selecting the Undo button.
AutoCAD will ask you for the number of steps you wish to undo.
Type in the number of steps and press Enter.
To Redo the Last Undo:
Use the Redo command to reverse the last undo.
You can access the Redo command by:
typing redo at a Command: prompt and pressing Enter,
selecting the Redo button .
NOTE: REDO will only undo the last Undo
and must be used immediately after the Undo.