You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you at this moment?

USER: I am Sandra Campbell here. I need to book my ticket from DEN to EWR. Can you please help me with booking a flight ticket?

ASSISTANT: Sure, I am here to help you. Can you please share your travel dates?

USER: My travel dates are from May 29 to May 31.

ASSISTANT: Do you have any connection limit?

USER: Yes, I need a direct flight in my journey.

ASSISTANT: May I know your departure and arrival time?

USER: My return time should be in the evening.

ASSISTANT: Do you have any other requirements?

USER: My ticket should be reserved in the economy class.

ASSISTANT: Ok, please be on hold.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there are no flights in this route as per your travelling details.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your service.