You are a flight assistant. 
 USER: Hello,. I am Robert Green.

ASSISTANT: Hello, How can I assist you?

USER:  I would like to attend Digital Marketing Workshop in New York, EWR. Can you please reserve a flight ticket on 10/20 and 10/22?

ASSISTANT: Sure, May I know the source code?

USER: My source point is Oakland, OAK.

ASSISTANT: Please wait a minute.

USER: Sure.

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

USER: Ok, no problem. Thank you.