ADD allows you to turn levels on within the current
display.

Enter the level number(s) for display and press <Enter>.

You can designate more than one level using one of the
following methods:

- Using commas to separate each level number
  For example: 1,2,10.

- Using a hyphen or dash to designate a series of levels
  For example: 3-12,14-20.

- Using a combination of commas and hyphens
  For example: 1,2,3-7,10.
