You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: I am Timothy Garcia. I need to book a flight ticket from DCA to JFK, Can you please help me for booking?

ASSISTANT: Sure, I can help you. Please let me know your travel dates.

USER: I would like to travel on 05/21 to return on 05/23.

ASSISTANT: Ok, may I know your specifications?

USER: I would be return on afternoon.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there is no flight available.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: You are welcome and thank you for choosing us.