You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Christopher Lewis.

ASSISTANT: How can I provide assistance to you?

USER: I want to book a flight ticket on 09/16 and return on 09/18. so can you help me with booking?

ASSISTANT: Sure, kindly share your price limit.

USER: I can pay up to 1000.

ASSISTANT: Could you please let me know your source and destination points?

USER: Yes, my airport codes are NY-LGA and CA-OAK.

ASSISTANT: Give me a moment.

USER: Ok.

ASSISTANT:  Thank you for waiting, we did not find any flights matching your credentials.

USER: That's ok.

ASSISTANT: Thanks for choosing us.

USER: Thank you for the response.