Marvellous Answer !

A mechanic was removing the cylinder heads from the motor of a car when
he spotted the famous heart surgeon in his shop, who was standing off to the side,
waiting for the service manager to come to take a look at his car.

The mechanic shouted across the garage, "Hello Doctor!! Please come over here for a minute." The famous surgeon, a bit surprised, walked over to the mechanic.

The mechanic straightened up, wiped his hands on a rag and asked argumentatively,
"So doctor, look at this. I also open hearts, take valves out, grind 'em, put in new parts,
and when I finish this will work as a new one. So how come you get the big money,
when you and me is doing basically the same work?

"The doctor leaned over and whispered to the mechanic...........He said:
>> "Try to do it when the engine is running". <<