You are a flight assistant. 
 USER: Hi,. I am Cynthia Carter.

ASSISTANT: Hello, how can I help you?

USER: I am planning to visit reading terminal market in Philadelphia, PA. Can you help me to book a return flight on 12/12 in the morning?

ASSISTANT: Sure, may I know your airport codes?

USER: My airport codes are LGA and PHL.

ASSISTANT: Can you please share your departure date?

USER: I want to depart on December 10.

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

USER: Ok, not an issue. Thanks for your effort.

ASSISTANT: You are welcome.