You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Jerry Hall.

ASSISTANT: Jerry, how can I assist you?

USER: There is a havoc caused by hurricane in the place where I am travelling. Can you help me in changing my reservation?

ASSISTANT: Sure, I can help you.

USER: Please check with the name Jerry Hill.

ASSISTANT: Let me check.

USER: Ok.

ASSISTANT: Please provide your preferred dates.

USER: I have changed my journey to 07/27 and would like to return on 07/29.

ASSISTANT: Could you share your airport codes?

USER: I would like to travel from DCA to SFO.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry, we could not find a flight on your planned dates.

USER: That's fine. Thank you for the information.

ASSISTANT: You are welcome.