getStates               getStates returns the list of states which have
                        zip codes which fall in a specified radius in
                        lower case format for use in choroplethrZip
getZipPop               getZipPop returns a data frame of zipcodes and
                        their population where the zip codes fall
                        within a given radius for use in choroplethrZip
getZips                 getZips returns the list of zip codes as a
                        character vector which have zip codes which
                        fall in a specified radius in lower case format
                        for use in choroplethrZip
zipRadius               The zipRadius Function
