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 shortly and said, "Yeah, I meant two- by-fours."
"All right. How long do you need them?"
The customer paused for a moment and said, "I'd better go check." After a while, he returned to the office and said, "A long time... we're gonna build a house!"