You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I provide assistance to you?

USER: I would like to make few changes in my existing reservation due to heavy rains in London, can you help me?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: Ok, my name is Christopher Parker.

ASSISTANT: Ok, please wait for a second.

USER: Sure.

ASSISTANT: We do not found any active reservation in your name.

USER: Oh! That's very sad to hear from you. Anyways, thank you for checking.

ASSISTANT: Thanks for making us to serve you.

USER: You are most welcome.