A fellow was window-shopping down the street, when he came upon a shop with a big display window that contained nothing but a clock.
Wondering what kind of shop this could be, he turned the knob and entered. A bell on the door rang, and the baleboss came out from the back.
"Yes, sir. Can I help you?"
"I was wondering, what would you charge to clean my watch?"
"Oh, I don't fix watches. I'm a mohel."
"You're a mohel? Well, what's with the clock in the display window there?"
The mohel shrugged, "So what would you put in the window?"
I haven't heard that one in years. Mazeltov