ROANOKE, Va. (AP) — Mitt Romney said Thursday that President Barack Obama doesn't have a clue about how business works. The Obama campaign shot back by saying that Romney doesn't know what he's talking about.

The Republican presidential nominee also criticized Obama for suggesting the creation of a secretary of business.

"We don't need a secretary of business to understand business. We need a president who understands business," Romney said during a visit to Integrity Windows, which is owned by a family that Obama praised during his convention speech.

Obama has floated the idea of the new post as a way to consolidate nine agencies that now deal with business matters, and as a way to eliminate bureaucracy. Obama has called it a "one-stop shop" for business owners.

Obama campaign spokeswoman Lis Smith responded to Romney's claims by saying that "the idea that Mitt Romney would help businesses grow as president doesn't match his record or his policies."

She said "Romney can lurch from false attack to false attack in the final days of this campaign," but that the public understands the president is the only candidate with "a concrete plan to move our country forward, grow our economy, and strengthen the middle class."