It was Halloween and three vampires went into a saloon and bellied up to the bar. 'What will you have?' the bartender asked. 'I'll have a glass of blood,' the first replied. 'I'll have a glass of blood, too, please,' said the second. 'I'll have a glass of plasma,' said the third. 'OK, let me get this straight,' the bartender said. 'That'll be two bloods and a blood light?'