You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. May I know your good name please?

USER: My name is Jack Robinson.

ASSISTANT: OK Jack, how can I assist you for today?

USER: I want to travel from DEN to EWR. Please help me for booking a ticket.

ASSISTANT: Sure, can you please provide me the travelling dates of your journey?

USER: Yes,my travelling dates will be from 09/22 to 09/24.

ASSISTANT: OK, please wait for a moment.

USER: Sure.

ASSISTANT: Thank you for waiting Jack. Sorry for the inconvenience, there is no flight found for this requirement.

USER: Oh!it's OK,thank you for helping me.

ASSISTANT: Thank you.