Thanks, hunhun and rani. I found the thread after posting one here... Sorry.
Anyway, I checked out Wing On web site, and realized that their mattress "protectors" are what I normally call mattress "pads". What I'm looking for is a waterproof "liner" type that would prevent the mattress pad and the mattress itself from getting wet (during the potty training periods in particular). Is that what you got, hunhun? Thanks so much for your help.
Sara.