Acknowledgments As hard as we have worked on this book, we could never have done it alone. Many people at SAS helped make this book what it is. To our many hard-working reviewers Carole Beam, Janice Bloom, Brent Cohen, Vicki Leary, Elizabeth Maldonado, Allison McMahill, Sandy McNeill, Randy Poindexter, Morris Vaughan, and Deanna Warner, we say,Thanks for hanging in there with us. To our copyeditor, Mary Beth Steinbach, and our designer, Kris Rinne, Thanks for making us look good. "To our production specialist, Karen Perkins, Thanks for rectifying all those wayward footnotes, mysterious font errors, and uncooperative images. And last but not least we would like to thank-faster than a speeding deadline, stronger than Microsoft Word, able to leap tall drafts in a single bound--our editor, Stephenie Joyner Outside the walls of SAS many other people also contributed to this book. In particular we would like to thank our readers. We love meeting you at conferences even if we seem a little shy. Without you, of course, there would be no reason to keep writing. To her co-workers-Tim Allis, Dana Drennan, Paul Grant, and Steve Nichols-Lora would like to say, Thanks for being so flexible when I needed to take time off to write. Most of all we would like to thank our families for their understanding andAcknowledgments As hard as we have worked on this book, we could never have done it alone. Many people at SAS helped make this book what it is. To our many hard-working reviewers: Carole Beam, Janice Bloom, Brent Cohen, Vicki Leary, Elizabeth Maldonado, Allison McMahill, Sandy McNeill, Randy Poindexter, Morris Vaughan, and Deanna Warner, we say, “Thanks for hanging in there with us.” To our copyeditor, Mary Beth Steinbach, and our designer, Kris Rinne, “Thanks for making us look good.” To our production specialist, Karen Perkins, “Thanks for rectifying all those wayward footnotes, mysterious font errors, and uncooperative images.” And last but not least we would like to thank—faster than a speeding deadline, stronger than Microsoft Word, able to leap tall drafts in a single bound—our editor, Stephenie Joyner. Outside the walls of SAS many other people also contributed to this book. In particular we would like to thank our readers. We love meeting you at conferences even if we seem a little shy. Without you, of course, there would be no reason to keep writing. To her co-workers—Tim Allis, Dana Drennan, Paul Grant, and Steve Nichols—Lora would like to say, “Thanks for being so flexible when I needed to take time off to write.” Most of all we would like to thank our families for their understanding and support