You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you today?

USER: As I am a event organizer for Culture, heritage and folk festivals, so look after all these festivals I want to book a flight to Houston, IAH. Can you please book me a flight ticket on the name Andrew Lee?

ASSISTANT: Sure, may I know on which dates you are willing to travel?

USER: Sure, 02/10 and 02/12 are my preferable dates.

ASSISTANT: May I know your source code?

USER: Sure, it's LAS.

ASSISTANT: Sorry, there were no flights found from your source.

USER: No issue, thank you.

ASSISTANT: Thank you for availing us.