Walter,

Static variables are usefull when subsequent calls to a routine should retain the variables previous value.

Example:

* Count parens in a string
LOCAL lcString
lcString = "(testing) (paren) (counting)"

ParenCnt("RESET")

FOR lnCnt = 1 TO LEN(lcString)
   ParenCnt(SUBSTR(lcString,lnCnt,1))
ENDFOR

ParenCnt("DISPLAYCOUNT")

RETURN

PROC ParenCnt( pcChar )
STATIC snOpen, snClose
IF pcChar = "RESET"
   snOpen = 0
   snClose = 0
   RETURN
ENDIF

IF pcChar = "DISPLAYCOUNT")
   ? "Open Parens: ", snOpne
   ? "Clsoe Parens: ", snClose
   RETURN
ENDIF
IF pcChar = "("
   snOpen = snOpen + 1
ENDIF
IF pcChar = ")"
   snClose = snClose + 1
ENDIF
RETURN

The static nature of snOpen and snClose allow them to act as accumulators for the open and close parens. The RESET option is required to clear any previous values out of those static vars.