You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Larry Smith.

ASSISTANT: How can I help you today?

USER: Please book a flight ticket on dates 01/18 and 01/20.

ASSISTANT: Sure, I will help you to book a flight ticket. Can you please share me your travelling airport codes?

USER: Sure, my airport codes are NY-EWR and CA-LAX.

ASSISTANT: Please give me a moment.

USER: Ok.

ASSISTANT: Sorry, no flights are available on your route.

USER: That's ok, thank you for the response.

ASSISTANT: Welcome, have a nice day. Thank you for choosing us.