How to show/hide Notes panel in powerpoint

I often use Notes panel to write some notes but I cannot find it one day. How to show/hide Notes panel in Normal view. 

At the bottom, right of the orange task bar, click Notes.

Click Notes to either show or hide your speaker notes.

IF you use powerpoint 2007 

Go to Options (from the File Menu) and choose "Advanced" on the left. In the "Display" section there is a configuration option called "Open all documents using this view". Change that to "Normal - outline and slide".