You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: I am planning to attend a business meeting in Denver, so please help me in booking a flight ticket from Charlotte.

ASSISTANT: Sure, I would be happy to help you. Help me with the source and destination airport codes?

USER: My airport codes are NC - CLT, CO - DEN.

ASSISTANT: When are you planning to travel?

USER: I want to fly on 12/22 and return on 12/24.

ASSISTANT: How much can you afford for the ticket?

USER: I can afford up to 1000.

ASSISTANT: May I know your good name?

USER: I am Carolyn Smith.

ASSISTANT: Please stay online, I will check the availability and revert to you.

USER: Sure.

ASSISTANT: Sorry we found no flights on your dates.

USER: Not an issue. Thank you.

ASSISTANT: Thank you for reaching us.