You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. May I know your good name please?

USER: Actually I want to change my existing reservation due to some climatic changes, can you help me? Sure, I am Charles Hill.

ASSISTANT: Sure, I am happy to help you. Wait a moment to search for that, I will revert you back.

USER: Ok.

ASSISTANT: Thank for be on hold, sorry to say, that there is no reservation found in our data base based on your name.

USER: Oh! that's fine.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your information.

ASSISTANT: It's our pleasure to help you.