You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Please book a ticket from HOU to SEA to meet my sister.

ASSISTANT: Sure, please share your journey dates?

USER: My travelling dates are Sept 15 and Sept 17.

ASSISTANT: Do you have any specifications?

USER: I want a direct flight.

ASSISTANT: Is there any class preference?

USER: No.

ASSISTANT: May I know your good name?

USER: I am Nancy Johnson.

ASSISTANT: Sorry, no flights found on your given details.

USER: Ok, Thank you for your service.

ASSISTANT: Thank you for choosing us.