PHP will build the array as you go. If $I (Msgs, Twts) = 4 and you ask for/put something in $MIG (Msgs, Twts)[$I (Msgs, Twts)+1] it adds a new cell for you.
@EWUMISC371 $MIG (Msgs, Twts)[$IDON (Msgs, Twts)'tknow]? You want to have the [] refer to "cells" 1-5 or whatever right? Am i following the analogy correctly?
You don't have an array called 'periods' any more. It's now $MONEYIGOT (Msgs, Twts)[], which I'll call $MIG (Msgs, Twts)[]. $MIG (Msgs, Twts)[] is the name of the spreadsheet.