You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: Jeffrey Clark here. I would like book a ticket from EWR to DEN.

ASSISTANT: Sure, I am here to help you out. May I know your travelling dates please?

USER: My travel dates are July 13 and July 15.

ASSISTANT: Do you prefer any halt?

USER: I would like to prefer a halt where Depart time should be evening and return time should be in the morning.

ASSISTANT: Jeffrey Clark, there are no flights available in your route.

USER: No problem, thank you for your time.

ASSISTANT: Thank you for reaching us.