A dentist has to remove a patient's tooth. 'I'll give you an injection so you
won't feel the pain,' he says. 'No I hate needles,' the patient cries. So the
dentist offers laughing gas. 'No, I'll suffocate!' the man wails. So the dentist
gives him a Viagra tablet. 'Wow!' the man gasps. 'I didn't know Viagra
worked as a painkiller.' 'It doesn't,' the dentist replies. But it will give you
something to hold onto when I pull out your tooth.'