You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: There is an event in White House, I got a invitation from White House  for the event, so I want to book a ticket from Phoenix.

ASSISTANT: That's good to hear. Then what are your planning dates?

USER: I am departing on 10/21 from Phoenix-PHX airport.

ASSISTANT: Ok, may I know your returning details?

USER: My return date from Washington-IAD airport is on 10/23.

ASSISTANT: May I know your respected name please?

USER: My name is Edward Parker.

ASSISTANT: Ok Edward, sorry to tell you that there are no flights available on your preferred dates. Do you like to prefer any other date to fly?

USER: No thanks, I will check for other alternatives.

ASSISTANT: Would you like to have any other help from our end?

USER: No, thank you for asking.

ASSISTANT: That's my pleasure.Thank you .