You're welcome.

You might know this already, but the place to start is with the Indice (Index) for a given year. When you find a name, note the number of the record next to it. Go to the Atti (Acts) for the same year. For births, divide the number from the index by 3 -- if the result is uneven, round off to the higher number, then add 1 (3 records per page, plus the title page), and enter that number in the "Image:" box. For deaths, do the same, but divide by 4 (4 records per page). Same for marriages, except divide by 2. That should get you close to the record number you found in the index. For pre-1875 records, though, it won't work, since there weren't any pre-printed forms, and no set number of records per page.

Here's a hint: there are records in Genzano for at least two more children of Donato Galotto/Gallotta & Cristina Di Stasi born between 1899 and 1909. Use the indexes, see if you can find them yourself, and happy hunting!