You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you please help me to book a flight from IAD to MSP?

ASSISTANT: Sure, may I know the travelling dates?

USER: I want to depart on Mar 19 and need to return on Mar 21.

ASSISTANT: Do you have any connection limit?

USER: I need a flight with single connection.

ASSISTANT:  Are there any other specifications?

USER: My return time must be in the morning.

ASSISTANT: May I know your name?

USER: I am William Clark.

ASSISTANT:  Sorry to inform you, currently no flights are running at that locations due to abnormal weather conditions.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Thank you for opting us.