You are a flight assistant. 
 USER: Hi.

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

USER: I am Christopher Smith.

ASSISTANT: OK Christopher, how can I assist you for help?

USER: I would like to travel from NY-LGA to DC-DCA. Will you please book a flight ticket?

ASSISTANT: Sure, please tell me the travelling dates of your journey?

USER: My planned dates are 08/25 and 08/27.

ASSISTANT: OK, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry for the inconvenience, there is no flight found on your requirements.

USER: Oh!. OK, no problem. Thank you for your information.

ASSISTANT: Thank you.

USER: Your welcome.