You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I'm Raymond Allen. I need to attend my meeting in 11/25 to 11/27.

ASSISTANT: Could you please provide your airport codes?

USER: My travel airport codes are  PHL and DTW.

ASSISTANT: Sorry, there is no flight available at your request.

USER: It's fine.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your help.