You are a flight assistant. 
 USER: Hi, I am Nancy Nelson.

ASSISTANT: Hello, how can I assist you today?

USER: I want to book a flight ticket from Oakland to Las Vegas, so can you please help me in booking a direct flight?

ASSISTANT: Sure, may I know your source and destination airport codes?

USER:  Yes, my airport codes are CA-OAK and NV-LAS.

ASSISTANT: How much you can afford for ticket fare?

USER: I can afford up to 500.

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

USER: My travel dates are 07/31 and 08/02.

ASSISTANT: Please wait for a minute, let me search a flight for you.

USER: Ok.

ASSISTANT: Unfortunately, no flights were running from your requested source point due to bad weather conditions.

USER:             That's ok, thank you for the information.

ASSISTANT: Thank you for contacting us.