info on cream sherry?

Hey everyone!
I was cleaning out our liquor cabinet of things that have been around for years and years, and have been opened and might not be the best to drink anymore. I've come across some interesting stuff... including a no-longer-liquid Baileys.
But anyway, here's my question. We have a bottle of cream sherry that's so old... well... dang, it's old. It probably belonged to my grandparents. It's been opened, and the cork is pretty decayed. Anyway, I'm a brave girl, and although the smell was pretty strong, I poored a little into a glass and had a very small taste. It tastes like raisins. I like raisins. Anyway, I was just wondering if it would be safe to drink. If anyone knows anything about cream sherry, let me know. Umm... until then... heck, a couple sips won't hurt. Raisins, guys, raisins!