You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I render you today?

USER: I am Thomas Thomas.

ASSISTANT: Ok.

USER: Can you help me booking a flight ticket from IAD to OAK?

ASSISTANT: Sure, we are perky to help you.

USER: Thank you.

ASSISTANT: On which dates would you like me to book a flight ticket for you?

USER: I will start on Dec, 27 and return on Dec, 29.

ASSISTANT: Ok, please wait a moment, let me search a flight for you.

USER: Sure.

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

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing us.