fetching rows

Let say we have a select that returns 100 rows.

I can fetch first 25 with simple sql:

BEGIN WORK;
DECLARE liahona CURSOR FOR SELECT * FROM films;
FETCH [FORWARD] 25 IN liahona;
CLOSE liahona;
COMMIT WORK;

but how I can fetch rows from 26 to 50? I mean withou fetching first 25. Or
can I skip first 25?

When i ask this you need to know that Im using PHP in web environment and
try do this to get more  performens from the script (now the script fetch
all rows, then jump to needed row)