You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I would like to attend a party at Washington, please help me in booking a ticket.

ASSISTANT: Sure, may I know your airport codes please?

USER: My airport codes are from PHX to DCA.

ASSISTANT: On which dates you like to travel?

USER: My journey dates are 03/16 and 03/18.

ASSISTANT: May I know your name please?

USER: My name is Carol Lewis.

ASSISTANT: I am sorry no reservation found on your route.

USER: Ok, thank you for your information.

ASSISTANT: Thank you for choosing us.