Do look me up the next time you're in London.

你下次到伦敦，一定要来看我。

Promise to look me up next time.

你答应我下次还来看我。

If you're ever in Xi 'an, look me up.

如果你来西安，一定要来找我。

Remember to look me up if ever you're here.

如果你再来这里，别忘了来看我。

Do look me up next time you are in town.

下次进城请一定来看我。