You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you help me to book a ticket from HOU to SEA?

ASSISTANT: Sure, can I know your name?

USER: Ok, my name is David Scott.

ASSISTANT: Thank you. May I know your travel dates?

USER: The dates of my journey are Dec 29 and Dec 31th.

ASSISTANT: Noted. Please wait for a while.

USER: Ok, take your own time.

ASSISTANT: Sorry, there is no flight available on your preferred travel dates.

USER: That is ok, thank you for assisting me.

ASSISTANT: You are most welcome.