Some men in a pickup truck drove into a lumberyard. One of the men walked in the office and said, "We need some four-by-twos." 

The clerk asked, "You mean two-by-fours, don't you?"

The man said, "I'll go check," and went back to the truck. He returned and said, "Yeah, I meant two-by-four."

"All right. How long do you need them?"

The customer paused for a minute and said, "I'd better go check."

After a while, the customer returned to the office and said, "A long time. We're gonna build a house."