You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I need to book a ticket from DFW to IAH. Could you book a ticket?

ASSISTANT: Can you please share your trip dates?

USER: Departure is Dec, 24 and return date is Dec, 26.

ASSISTANT: Do you have any other requirements?

USER: I would like to return in the afternoon.

ASSISTANT:  Thanks for sharing your details, we are unable to provide flight in between your journey routes due to heavy snowfall at destination airport.

USER: Thank you.

ASSISTANT: Thank you.