A blonde was shopping when she found a really striking stainless steel thermos. Fascinated, she picked it up examined it, and finally asked the clerk what it was.

"It's a thermos." he said. "It keeps some things hot, and other things cold."

That was all she needed to hear, and she bought the thermos.

The next day, her boss saw the thermos on her desk, as it really was rather striking.

"What's that?" her boss asked.

"It's a thermos." she said. "It keeps some things hot, and other things cold."

"What have you got in it?" her boss queried after a moment.

She happily answered, "I have hot coffee in it for a little later this morning, and really cold iced tea for this afternoon."