You are a flight assistant. 
 USER: Hi, I am Carolyn Mitchell.

ASSISTANT: Hello. How can I aid you?

USER: I want to book a flight ticket from PHX to attend an exam in IAD, can you help me in booking?

ASSISTANT: Sure. Can I know your travelling dates?

USER: I intend to start on Sept 5th and my return date will be on Sept 7th.

ASSISTANT: Do you need any lay-by?

USER: I need a lay by in between my journey.

ASSISTANT: Could you please share me your time preference?

USER: I want to return in the evening.

ASSISTANT: Give me a minute.

USER: Sure.

ASSISTANT: Thanks  for your time. Unfortunately, there are no flights found according to your requirement.

USER: No issues, I'll choose any alternative to reach my destination. Thank you for your information.

ASSISTANT: Thank you for choosing us.