I was having trouble with my computer.

So I called Harold, the computer guy, to come over.  Harold clicked a couple of buttons and solved the problem. He gave me a bill for a minimum service call.

As he was walking away, I called after him, So, what was wrong?
He replied, It was an ID ten T error.

I didnt want to appear stupid, but none the less inquired, An ID ten T error? Whats that in case I need to fix it again?

Harold grinned.Havent you ever heard of an ID ten T error before?

No, I replied.

Write it down, he said, and I think youll figure it out.

So I wrote down:

I D 1 0 T

I used to like Harold.