gistfile1.txt

      CARD_COMPANIES = { 
        'visa'               => /^4\d{12}(\d{3})?$/,
        'master'             => /^(5[1-5]\d{4}|677189)\d{10}$/,
        'discover'           => /^(6011|65\d{2}|64[4-9]\d)\d{12}|(62\d{14})$/,
        'american_express'   => /^3[47]\d{13}$/,
        'diners_club'        => /^3(0[0-5]|[68]\d)\d{11}$/,
        'jcb'                => /^35(28|29|[3-8]\d)\d{12}$/,
        'switch'             => /^6759\d{12}(\d{2,3})?$/,
        'solo'               => /^6767\d{12}(\d{2,3})?$/,
        'dankort'            => /^5019\d{12}$/,
        'maestro'            => /^(5[06-8]|6\d)\d{10,17}$/,
        'forbrugsforeningen' => /^600722\d{10}$/,
        'laser'              => /^(6304|6706|6709|6771(?!89))\d{8}(\d{4}|\d{6,7})?$/
      }