multi.menu presents the user with a menu of choices
labelled from 1 to the number of choices. The user may choose
one or more options by entering a comma separated list. A range
of values may also be specified using the ":" operator. Mixed
expressions such as "1,3:5, 6" are permitted.
If allow.zero is set to TRUE, one can select `0' to exit
without choosing an item.
multi.menu(choices, title, header, allow.zero = TRUE)Character vector of labels for choices
Title printed before menu
Character vector of length 2 giving column titles
Permit 0 as an acceptable response
Numeric vector giving the numbers of the options selected, or 0 if no selection is made.
menu.