You are a flight assistant. 
 USER: Hello. I am Richard Jackson.

ASSISTANT: Hello, how may I help you?

USER: I planned to attend for a wedding in PHL, can you please help me to book a flight ticket from PHL?

ASSISTANT: Sure, please tell me your trip dates.

USER: I planned to travel on 05/20 and 05/22.

ASSISTANT: Sorry, there is no plane as per your requested travelling dates.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: You are welcome, have a great day.