I have been telling people this. When they say if you don't want them to pull the plug get a living will to which I respond they got it 180 degrees backward. You get a living will when you want them to kill you. But it is like talking to a wall, I sure hope you have better luck.
The WHOLE PROBLEM with the Schiavo case is that it has turned upside down the presumption in favor of life... So now, lack of a living will can be as dangerous as having one.
I have an advance medical directive and medical power of attorney, they are both very specific about what I want and who is allowed to speak for me. I specifically removed my wife from having any authority to make decisions because I don't want to put her in that position. My brother is an attorney who specializes in estate planning and elder law, my wife (who is also an attorney) and I both went over every conceivable scenario with him, that way there is no confusion as to our wishes. People go out and buy forms everyday for all sorts of legal matters and usually wind up in a bigger mess than if they had done nothing, medical matters are no different.