You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I am Amy Turner. Please book a flight ticket on dates 09/17 and 09/19.

ASSISTANT: Sure, may I know your origin and destination airport codes?

USER: My airport codes are DFW and PHL.

ASSISTANT: Do you have any specific time to depart and return?

USER: I would like to depart in the evening and I am ok to return at any time.

ASSISTANT: Thank you for your details, please wait for a while.

USER: Ok.

ASSISTANT: Sorry we don't have any flight available in the morning time.

USER: That's ok.

ASSISTANT: Thank you for reaching us, hope to assist you better next time.

USER: Thank you for the information.