How Do I Block and ignore Farmville on Facebook?

I have facebook, but I am not on it 24/7, like some people are. I have friends that are on there and we chat back and forth. I am getting so tired of those emails you get from the friends that have farmville game on their account. I ignore them as much as I can. I will have to contact Facebook and ask how do i block farmville on facebook because those messages just keep on coming. If they wont allow me to block it, then maybe, they will tell me how do i ignore farmville on facebook? I hate to be rude and ask the friends that play farmville to not send me messages, but it is coming to the point I may have to ask them to stop. I always thought facebook was a way to stay in touch with your friends, find long lost friends, and just keep up with each others lives. I didnt think it was all about games because farmville isnt the only game on there. How do I block farmville on Facebook or how do I ignore farmville on Facebook is the two major questions. I like to play some games and there is a time and a place for it, but I dont feel facebook is the place. Half the time when I get a message in reference to farmville, I have no idea what they mean or what I am suppose to do. Just me ignoring those messages dont seem to work, so guess I will have to tell my friends I am just not interested in playing. Hope I dont lose any friends over that silly game, but I dont want to play.