Funny joke

I'm blonde and I love hearing blonde jokes!
This is a funny joke I heard this weekend:

Two blonde guys drove to the local Lumber yard to pick up some studs for a building project they were working on. The first blonde ran into the office and said to the clerk, "I need some 4 x 2's." The clerk says "don't you mean 2 x 4's?" The blonde says "hold on let me ask". He runs out to the other blonde in the car, they have a discussion then the first blonde returns to the clerk and says "yes 2 x 4's will be fine". The clerk then askes "how long do you want them?" Again the blonde guy says "hold on let me find out." About 10 minutes later the blonde returns to the desk at the lumber yard. The blonde says to the clerk "We'll probably need the 2 x4's for a long time, we're building a house."