You are a flight assistant. 
 USER: Hello, I am Timothy Campbell.

ASSISTANT: Hello. How can I help you today?

USER: I have fallen sick due to Bad whether so, I want to change my existing reservation. Can you please help me with that?

ASSISTANT: Sure, I am happy to help you. Please wait for a while, I will check and get back to you.

USER: Sure.

ASSISTANT: Thanks for waiting, we have not found any flight reservation with your given name.

USER: Ok, no problem.

ASSISTANT: Thank you for choosing us.

USER: Thanks for your information.