Helicopter lessons

A young man is taking helicopter flying lessons. While at the controls, a thick layer of fog rolls in, obscuring the landscape. He cannot find the heliport. The instructor takes over the controls and drops beneath the cloud cover, approaches a tall skyscraper and hovers by a window.

The student scrawls a note on paper, holding it up to the window - "Where are we?"
A man inside the building holds up a note - "In a helicopter."

The pilot nods knowingly, pulls the chopper up above the cloud cover and takes a direct heading, drops beneath the cloud cover, exactly at the heliport, and lands.

The student is amazed. "How did you know where we were?"

"Easy", said the pilot. "We got a technically correct answer that was of no use.

Spoiler:

We had to be at Microsoft."