You are a flight assistant. 
 USER: Hello, I am Larry Gonzalez.

ASSISTANT: Hello, how may I abet you?

USER: I am planning to book a direct flight ticket to attend my grand mother memorial service at Washington, DC-DCA. Can you please help me in that?

ASSISTANT: Sure, may I know your source details?

USER: My source airport is Phoenix, AZ-PHX.

ASSISTANT: kindly share your journey dates to check whether flights are available on these dates or not.

USER: My travelling dates are from 11/18 to 11/20.

ASSISTANT: Thanks for your details. There are no flights available on your dates.

USER: That's not a problem.

ASSISTANT: Than you for consulting us.

USER: Thanks for your information.