Regional Location Detector UK - repost

Hi, We have a client with a website that wants the users UK location to be picked up and depending on which region they're in it will display a specific advert for that region. The regions are: North East North West Yorkshire and The Humber East Midlands West Midlands East of England London South East South West And if the user isn't in any of those / in another country it will default to 'London' The website is built + designs are given we just need this functionality integrating. Thank you