You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I oblige you today?

USER: Will you please help me to book a flight ticket from IAD to PHX?

ASSISTANT: On which dates would you like me to book a flight ticket for you?

USER: My journey dates are Oct, 25 and Oct, 27.

ASSISTANT: Do you have any preferences?

USER: I need direct flight.

ASSISTANT: On what name, do I need to reserve the ticket?

USER: Kimberly Collins here.

ASSISTANT: Sorry, no flights are available as per your requirements.

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for opting us.