You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Larry Roberts.

ASSISTANT: How may I support you today?

USER: I need to attend my graduation day in my college. Can you book the flight ticket from Atlanta to LGA?

ASSISTANT: Sure, please provide your departure and arrival dates?

USER: Sure, I will start my journey on 12/21 and return on 12/23.

ASSISTANT: Ok, help me with your source airport code?

USER: My source airport code is ATL.

ASSISTANT: Ok, please wait for some time.

USER: Sure, take your own time.

ASSISTANT: There are no flights found on your requested dates. Thank you for reaching us.

USER: That's ok, no problem. Anyway thank you for your euphoric help in providing information regarding flight availability.