This is an old revision of the document! Development Tips Seven Habits of Highly Effective Programmers C++ The Rule of Three Regular Expressions US Phone Number: /^1?[-. ]?([(]?\d\d\d[)]?[-. ]?)?\d\d\d[-. ]?\d\d\d\d\s*([eE]?[xX][tT]?\s*\d{1,4})?$/