You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: I am planning to book my ticket from DEN to MSP. Can you help me?

ASSISTANT: Sure, let me know your travel dates please?

USER: I am planning my depart on Dec 18 and return Dec 20.

ASSISTANT: Do you have any specific depart and arrival timings?

USER: Please make sure that depart in evening and return in morning.

ASSISTANT: May I know your connection limit?

USER: Make sure that connection limit is 1.

ASSISTANT: Ok, is there any class preference?

USER: No class preference is required.

ASSISTANT: Do you have any airline preference?

USER: I am ok with any airline.

ASSISTANT: May I know your good name please?

USER: Virginia Thomas.

ASSISTANT: Sorry to inform you that there are no flight services available on your given details.

USER: Thank you for checking.

ASSISTANT: Thanks for contacting us.