Maybe SCROLLHEIGHT=AUTO, would help?
TABLE FILE GGSALES
SUM UNITS DOLLARS
BY REGION BY ST BY CITY BY DATE
ON TABLE SET SHOWBLANKS ON
ON TABLE SET BYDISPLAY ON
ON TABLE SET PAGE NOLEAD
ON TABLE SET STYLE *
TYPE=REPORT, BORDER=LIGHT, BORDER-COLOR=RGB(220 220 220), FONT=ARIAL,
HFREEZE=ON, SCROLLHEIGHT=AUTO, $
TYPE=TITLE, BACKCOLOR=RGB(220 220 220), $
TYPE=DATA, BACKCOLOR=(BY=B3 RGB(245 245 245) WHITE), $
END
The scrollable area will expand vertically for the size of the iframe. Or if the rows all fit in the iframe then no scroller.