96 Buick LeSabre Keyless entry remote?

[Down With The Clown]

Okay. I got my grandpa's car after he passed away and he hadn't used it much in the last year he was here and the keyless entry remote didn't work so I opened it up and the batteries were like corroded in there and my step dad took one out, not seeing the other one, and put it on the counter and then like a week later I went to Radio Shack and bought a replacement and the guy put it in. He only saw one battery in there so he only put one in so later I went out to my car and noticed it still didn't work so I went back in and told him and the manager heard and said put a thicker battery in and so he did. I mentioned that it might have originally had two batteries in it and the manager said that I was probably mistaken. I know now that there were 2 batteries for sure and since they put the thick one in, only the lock button on my remote works. Is that because there is only one battery? I don't want to buy a whole new remote if I don't have to so will putting 2 of the smaller batteries in, like the originals, make all the buttons work? Please help; it sucks having to stand in the cold trying to get the key in the whole and my friends especially hate waiting.

Thanks