This Questions feature should not be taken as a substitute for reading the web book. I have tried hard to make it easy to find information in this book by providing a Table of Contents and a Subject Index. I say this because many questions I receive are answered within the web book in better detail than is possible via email. Also, you would obtain your information much more quickly if you find it for yourself rather than wait for me to respond. However, do not hesitate to ask questions on any material in my web book that you find hard to understand.