You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: I would like to meet my friend on his birthday, can you please book the flight ticket from DEN to EWR?

ASSISTANT: Ok, may I know your travelling dates please?

USER: I will depart on 09/13 and return on 09/15.

ASSISTANT: May I know your name?

USER: My name is Richard Roberts.

ASSISTANT: Sorry to inform you, there is no flight available for you.

USER: Not an issue, anyway thank you for checking.

ASSISTANT: Richard Roberts, most welcome.