"An ID Ten T Error" joke

Young Judy was having trouble with her computer, so she called Tony, the computer guy, over to her desk.Tony clicked a couple buttons and solved the problem. As he was walking away, Judy called after him, "So, what was wrong?"

He replied, "It was an ID Ten T Error."

A puzzled expression came over Judy's face. "An ID Ten T Error?

What's that? In case I need to fix it again."

Tony gave her a grin. "Haven't you ever heard of an ID Ten T Error before?"

"No," replied Judy.

"Write it down," he said, "and I think you'll figure it out."She wrote... I D 1 0 T