Roller Coaster

"What happened?" asked the hospital visitor of the
heavily bandaged man sitting up in bed.

"Well, I went down to Margate at the weekend and
decided to take a ride on the roller coaster. As
we came up to the top of the highest loop, I noticed
a little sign by the side of the track. I tried
to read it but it was very small and I couldn't make
it out. I was so curious that I decided to go round
again, but we went by so quickly that I couldn't see
what the sign said. By now, I was determined to read
that sign so I went round a third time. As we reached
the top, I stood up in the car to get a better view."

"And did you manage to see what the sign said this time?"
asked the visitor.

"Yes."

"What did it say?"

"Don't stand up in the car!"