There are some questions that are asked so frequently that people have put them in a document called a "FAQ" (for "Frequently Asked Questions") along with their answers in the hope that if the answers are so easily available then people won't have to ask these questions so often.

For some reason this plan doesn't work very well and people rarely check the FAQ before asking questions. Anyway, this question is answered in the FAQ.

How can I use a variable as a variable name?