You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Please book a flight ticket in my preferable travel dates Mar, 27 and Mar, 29.

ASSISTANT: Sure, can I know your source and destination airport codes?

USER: DEN and HOU are my airport codes.

ASSISTANT: Do you have any other preferences?

USER: I need to depart at morning time.

ASSISTANT: May I know your class preference?

USER: No, thanks.

ASSISTANT: Do you prefer a connecting flight?

USER: I am looking for connecting flight.

ASSISTANT: May I know your name?

USER: Sarah Taylor here.

ASSISTANT: Sorry, we could not find any flights on your requested dates.

USER: That's ok, thank you for the information.

ASSISTANT: Thank you for choosing us.