Why the Battle for AOL between Microsoft and Google?

Why does Microsoft want to buy AOL?

That is the big question isn’t it?
Well here is what I heard and I think it makes sense. Right now Google gets about 25% off their searches (and possible revenue) from AOL. If Microsoft is going to buy AOL they would change the search to use MSN search instead and this would be a huge blow to Google in terms of earnings. There it is in a nutshell at least that is my opinion