Ctrl - Y or the Redo button will do this, so they can be used.
Ctrl + Z
or
Ctrl + Backspace
undo button
yes
Undo Button
Undo Button
The redo button reverses the action of the undo button.
Some versions might have a button, but you can go to 'edit' and hit 'undo.' You can also hit control + z on your keyboard.
undo
The undo button. If you click the undo button and want to redo what you just undid, hit the redo button
The undo button.
The Delete key will do it, once you have those cells selected. You can also use the Undo button on the screen, or Ctrl - Z.
Undo
The undo button for firefox is positioned to the left of the address bar.
There isn't an undo button within Moshi Monsters.