>Well, at least I see that the Between syntax in the Where clause is incorrect:

>And (ET.date BETWEEN ldStartCurr and ldEndCurr ;
>  OR ET.date BETWEEN ldStartPrev and ldEndPrev)

>Should be something like

> And (between(ET.date,ldStartCurr,ldEndCurr) ;
>  OR between(ET.date,ldStartPrev,ldEndPrev))

>What happens if ET.date is empty or NULL?

Actually, they are both correct, but the first is more SQL-server compatible.