Looking for a phrase in your notes, or looking for a note that contains a certain word? Enter it in the Search box 
and click the magnifying glass to start the search. Use the down arrow next to the magnifying glass to refine the search area.
When the search is completed, the Search box will be replaced with a highlighted area (see the picture). If there's more than one occurrence of your search term, you can click through the results using the Previous Match and Next Match arrows in the highlighted area.
The page tab of every page that has the search term on it is highlighted. In addition, you can see a list of every page with the search term on it by clicking View List in the highlighted area. This will open the Page List task pane with a list of every page with the search term in it.
