You can always go to a pill identifying site (google "pill identifier") and enter the details as to what the pill looks like. You will get results telling you what med, and what strength the tablet is. Or, you could ask your pharmacy.
Lorazepam and Ativan are the same medication. Ativan is the brand name, Lorazepam is the generic.
Adivan is the same thing as lorazepam. Just generic