The Prepositional Phrase ... now, this is funny !!

Harry is getting along in years and finds that he is unable to
perform
sexually. He finally goes to his doctor, who tries a few things
but nothing seems to work. So the doctor refers him to an
American Indian medicine man.

The medicine man says, 'I can cure this.' That said, he throws
a white
powder into a flame, and there is a flash with billowing blue
smoke.

Then he says, 'This is powerful medicine. You can only use it
once a
year. All you have to do is say '123' and it shall rise for as
long as you wish!'

The guy then asks, 'What happens when it's over, and I don't
want to
continue?'

The medicine man replies: 'All you or your partner have to say
is 1234, and it will go down. But be warned--it will not work
again for another year!'

Harry rushes home, eager to try out his new powers and prowess.
That night he is ready to surprise Joyce. He showers, shaves,
and puts on his most exotic shaving lotion.

He gets into bed, and lying next to her says, '123.' He
suddenly becomes more aroused than anytime in his life .. just
as the medicine man had promised.

Joyce, who had been facing away, turns over and asks, 'What did
you say 123 for?'

And that, my friends, is why you shouldn't end a sentence with a
preposition!