Send CTRL-ALT-DELETE to a Windows Virtual Box computer from a Macintosh

When you start a Windows 7 or equivalent server machine, to log in, you need to press CTRL-ALT-DELETE on the keyboard to get the login page. To send Control-Alt-Delete to a Windows virtual machine in Virtual Box from a Macintosh on a Macintosh laptop press the fn – Command  – Delete back  keys on a Macintosh desktop …