# File lib/randexp/randgen.rb, line 65
  def self.phone_number(options = {})    
    case options[:length]
    when 7  then  /\d{3}-\d{4}/.gen
    when 10 then  /\d{3}-\d{3}-\d{4}/.gen
    else          /(\d{3}-)?\d{3}-\d{4}/.gen
    end
  end