An elderly couple walk into a doctor's office. The man tells the doctor, "Doctor, we want to have a baby." The doctor replies,"At your age I don't think it's possible, but I'll give you a jar, come back in a few days with a sperm sample." So the couple comes back a few days later.They give the doctor an empty jar. The doctor says,"I was afraid of this." The old man says,"No, it's not what you think. I tried it with my left hand. I tried it with my right hand. She tried it with her left hand. She tried it with her right hand. She tried it with her teeth in. She tried it with her teeth out. But we couldn't get the lid off the jar."