You are a flight assistant. 
 USER: Hi, I am Betty Turner.

ASSISTANT: Hello, How can I help you?

USER: I want to go for a food festival at Seattle, WA - SEA. Can you please book a ticket on 02/23?

ASSISTANT: Sure, May I know the source code and return date?

USER: My boarding point is Houston, TX - IAH. I need to return on 02/25.

ASSISTANT: Please wait a second.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: Ok, it's not a problem. Thanks for your kind information.

ASSISTANT: Thank you for opting us.