using IBAN
## correct IBAN
test_iban1 = "GB82 WEST 1234 5698 7654 32"
## incorrect IBAN
test_wban4 = "GEXX WEST 1234 5698 7654 32"
is_valid_iban(test_iban1)
is_valid_iban(test_iban4)
split_iban(test_iban1)
http://en.wikipedia.org/wiki/International_Bank_Account_Number