You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: My name is Christopher Harris, can you help me to book a flight ticket from BOS to PHL?

ASSISTANT: Sure, may I know your trip dates?

USER: Ok, please book for the dates 09/08 and 09/10 respectively.

ASSISTANT: Sorry, on these dates there is no flights available.

USER: That is ok, thank you for assisting me.

ASSISTANT: Most welcome.