You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Nancy Davis. Please help me in booking a flight ticket from DFW to LGA.

ASSISTANT: Sure, can you please let me know your travelling dates?

USER: 07/19 and 07/21 are my preferable travel dates.

ASSISTANT: Do you require any specifications in your journey?

USER: I need a connecting flight and my depart time should be at morning.

ASSISTANT: Do you have any airline preference?

USER: No.

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: Ok, not a problem.

ASSISTANT: Thank you.

USER: Thank you for the information.