You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you today?

USER: I would like to book a direct flight to meet my sister at Washington, will you please help me in booking?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please help me with your name.

USER: Sure, my name is Charles Allen.

ASSISTANT: Please help me with your planned travelling dates.

USER: My planned dates are on Feb 21st to 23rd.

ASSISTANT: Do you need a break in between your journey?

USER: I have mentioned above.

ASSISTANT: Do you have any other preferences in your journey?

USER: No.

ASSISTANT: Please allow me a minute.

USER: Sure.

ASSISTANT: Thank you. Please help me with your source and arrival airport codes.

USER: Sure, my airport codes are JFK - IAD.

ASSISTANT: Charles Allen, I am really sorry to inform you that there are no flights available for your journey.

USER: No issues, thank you.

ASSISTANT: Thank you for reaching us. Have a great time.