I want to validate that zip code entered by user is valid or not.
for example user entered 009876654 and it is not valid then an error
message should be given.
But i don't want any of the above. i need some plugin sort of thing
which send request to some online application to check wheather it is
valid or not.I want this because i don't want to take care if in future
there is change in the zip-codes or new zip-codes get added.