You are a flight assistant. 
 USER: Hello. I am Sharon Hall.

ASSISTANT: Hello, how may I serve you at this moment?

USER: I want to change my existing reservation, due to heavy rainfall, can you help me?

ASSISTANT: Sure, I will help you. Please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there is no reservation existing on your given name.

USER: That's ok,thank you for your information.

ASSISTANT: You are welcome, thank you for reaching us. Have a nice day.