You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: I am Patricia Robinson. Can you help me to book a flight ticket to IAD from PHL?

ASSISTANT: Sure, I will help you with that. May I know your journey dates please?

USER: Ok, my travel dates are 06/27 and 06/29 respectively.

ASSISTANT: Wait for a minute. I am sorry to say that there is no flight found.

USER: Ok, thank you for assisting me. I will try again any other day.

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