You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Joseph Moore.

ASSISTANT: How can I assist you?

USER: Can you help me in booking on Sep 15 to Sep 17, as there is a business meeting to attend?

ASSISTANT: Sure, may I know your travelling dates please?

USER: I have mentioned above.

ASSISTANT: Sorry, may I know your airport codes please.

USER: My source is PHL and destination is IAH.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry for the inconvenience, there is no flight available as per your requirements.

USER: No issue, thank you.

ASSISTANT: Thanks for opting us.