J-Word Play #1

Edit: 11/04/09 - No one told me until recently, but apparently the grammar of the punchline I was using was a little off. See answer for explanation.

Recently I've begun to take an interest in Japanese riddles (なぞなぞ) and puns (だじゃれ). Although I sometimes need them explained to me, I've found that I enjoy learning and sharing them (I've even made a couple of my own). They are by no means pivotal resources, but they're a good way to remember some vocabulary.

Starting with this post, I intend to periodically share some that I've collected over the course of my time here. I apologize in advance to those of you who don't speak any Japanese - I'll explain them, but I'm afraid the novelty of the Japanese word play may be lost. Without further ado, the Word Play of the day (apologies if I messed up any grammar in this one - I had to have someone explain it to me, so I've reconstructed it to the best of my memory):

男の二人は道を歩いて、一人はかつらをつけている。彼は突然に転ぶ。他の男は何を言うか？

(Two guys are walking on the street, and one of them has a toupee. He trips and falls. What does the other one say?)

Answer

X「あっ！けがあるか？」

O「あっ！けがないか？」

The joke in this one is that け (+ が as an assisting particle here) means hair, and けが means injury. So the solicitous friend could either be asking if his fallen comrade has his hair or if he has an injury. Edit: So it's more natural to use ない here. "You're not hurt?/You have no hair?"