You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I am Ashley Walker. Can you help me in booking from Jun 17 to Jun 19, as there is a musical concert to attend?

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

USER: My source is SFO and destination is PHL.

ASSISTANT: Ok, please give me a moment.

USER: Sure.

ASSISTANT: Sorry, there is no flight available on your requested dates.

USER: No issue, thank you.

ASSISTANT: You are most welcome.