Using Undo and Redo
The Undo feature lets you delete the last change made to your file. As you can imagine, this is a handy feature. If you suddenly make a change or mistake you do not want to keep, you can simply undo your action.
Word 2003 remembers up to 300 actions in a document and allows you to undo any or all of them as long as you haven't closed the document first.