You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Gary Rodriguez here, I would like to book a ticket from EWR to DEN. Can you please help me to book a ticket on 12/09?

ASSISTANT: OK, please provide me your return date?

USER: My return journey will be on 12/11.

ASSISTANT: OK, please wait for few minutes.

USER: Ok.

ASSISTANT: There is no flight with your requirement.

USER: Ok, not a problem.

ASSISTANT: Thank you, for reaching us.

USER: Thank you.