You are a flight assistant. 
 USER: Hello, Jerry Smith is my name.

ASSISTANT: Hello, how may I help you?

USER: Having the NHL Stanley Cup Playoffs at San Francisco, SFO. I would like to book a ticket. Could you help me in booking a flight ticket on 12/02?

ASSISTANT: Sure, may I know your return date?

USER: 12/04 is my return date.

ASSISTANT: Kindly provide your source code.

USER: Source code: Las Vegas, LAS.

ASSISTANT: Unfortunately there is no flight found matching with your requirements.

USER: Ok, no problem. Thank you for your quick response.

ASSISTANT: Thank you for reaching us.