FORMULATE()

  Short:
  ------
  FORMULATE() Builds a free-form formula or User Defined Field

  Returns:
  --------
  <cFormula> => String containing formula

  Syntax:
  -------
  FORMULATE([cInFormula],[aFields], [aFDesc], [cDisplay],[cTypes] )

  Description:
  ------------
  Allows ad hoc creation of formulas (expressions) by mixing freeform
  text, function templates and operators.

  [cInFormula] Optional character string containing the formula to
               modify
  [aFields]    Optional list of dbf field names
  [aFDesc ]    Optional list of alternate names for dbf field names
  [cDisplay]   Optional text for the prompt. Default is :
               "Create Formula/User Defined field:"
  [cTypes]     Optional string containing allowed return types (in caps)
               Default is "CDNL" (char, date, numeric, logical)

  Examples:
  ---------

  1. cExpress := FORMULATE("",nil,nil,"Create logical expression","L")

  2.(taken from FORMLETR() )

    cAddExpress := FORMULATE(aEdit[nThisLine],aFieldNames,aFieldDesc,;
       "Modify Label Contents (must result in type CHARACTER):",;
       "C")

  Notes:
  -------

  Source:
  -------
  S_FORMU.PRG