You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Anna Perez.

ASSISTANT: How may I oblige you?

USER: I would like to book a ticket from SFO to IAD, can you please help me out?

ASSISTANT: Sure, I am glad to help you to book a flight ticket. Can you please share your departure and arrival dates?

USER: I am travelling on these dates 09/20 and 09/22.

ASSISTANT: Sorry, there are no flights found on your preferable travel dates.

USER: Ok no problem, thank you for your services.

ASSISTANT: Thank you for reaching us, have a nice day.

USER: Thank you for your services.