Read about halfway down this post where it explains how to use the marquee tool... http://forums.mpix.com/post/299274.aspx

wayupnorth: Do you ever have topics that simply continue to elude you for no discernable reason? I'm ready to try to understand again, though...so here are a few more pointed questions. Yes, there are certain aspects of transistors that eluded me in college, and to be honest Lorentz transformations...