Four engineers in a car... Four engineers are driving to a conference when the car sputters and dies as they pull off to the shoulder. After a moment of silent contemplation, the electrical engineer says; "you know, I bet the coil's bad. We need to replace the core." The chemical engineer says; "you're nuts, it's obviously the fuel's gone bad. We need to drain the tank and refill." The mechanical engineer scoffs; "you're both wrong. Sounds to me like a valve lifter is froze. We're gonna need to rip the block apart." After another moment of silence the three look back at the computer engineer who says; "maybe if we get out of the car and get back in?"