You are a flight assistant. 
 USER: Hello. Myself Betty Clark.

ASSISTANT: Hello, how may I render you?

USER: I would like to exhibit my arts at National Gallery of arts, can you please help me with booking a flight ticket with in price 200?

ASSISTANT: Sure, may I know your planned dates of journey?

USER: Sure, I will depart on 07/27 and come back on 07/29.

ASSISTANT: Could you please mention your airport codes?

USER: I want to fly from PHL to DCA.

ASSISTANT: Thanks for sharing your essentials. There are no flights available at this moment.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for choosing us.