twSplitTxt( InString, LineLen, MaxLines )
 ----------------------------------------------------------------------------
     Splits a long string into parts at a space if possible.  InString
     may be 64K.

     This function derives from a similar one by Rick Spence.

       Arguments:

     InString - 'C' String to be processed.

     LineLen  - 'N' Length of line to aim for.

     MaxLines - 'N' Maximum number of lines allowed.

       Return:

     An array of string with MaxLines as its maximum number of
     elements.

       Example:

     sArray := twSplitTxt( MemoField )