You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: Can you please reserve a flight ticket from DEN to EWR for my business meeting?

ASSISTANT: Sure, May I know the travelling dates?

USER: Thank you, my boarding is on June 20 and please book my return ticket on June 22.

ASSISTANT: Do you have any connection limit?

USER: Sure, I will prefer single connection.

ASSISTANT: Is there any other requirements?

USER: No.

ASSISTANT: May I know your name?

USER: Sure, my name is Betty Harris.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: Oh! Sad to hear that. Anyway, I will find another alternative. Thank you for checking.

ASSISTANT: Thank you for reaching us.

USER: Welcome.